RUSSIAN JOINT STOCK COMPANY
GAZPROM

SYSTEM OF REGULATORY DOCUMENTS IN CONSTRUCTION

CODE OF CONSTRUCTION RULES
MAIN GAS PIPELINES

CODE OF RULES FOR CONSTRUCTION
LINEAR PART OF GAS PIPELINES

EARTHWORKS

SP 104-34-96

Approved by RAO Gazprom

(Order dated September 11, 1996 No. 44)

Moscow

1996

SP 104-34-96

Set of rules

Code of Rules for the Construction of Main Gas Pipelines

Code of the regulations on construction of trunk gas pipelines

Date of introduction 1.10.1996

Earthworks production

Developed by the Highly Reliable Pipeline Transport Association, RAO Gazprom, JSC Rosneftegazstroy, JSC VNIIST, JSC NGS-Orgproektekonomika.

Under the general editorship

acad. B.E. Patona, Ph.D. tech. Sciences V.A. Dinkov. prof. O.M. Ivantsova

INTRODUCTION

In order to ensure year-round construction and the possibility of flow-mechanized performance of the entire complex of construction and installation works, especially in difficult conditions, compliance with the design parameters of pipeline elements during laying and the requirements for the reliability of their operation during operation, modern progressive methods of organizing and technologies for the production of works, quality control and acceptance of earthworks in various climatic and soil zones.

The Code of Rules summarizes the results of research and design development, as well as best practices in earthworks, accumulated by construction organizations in domestic and foreign practice in the construction of linear facilities.

This joint venture proposes new methods for the construction of main pipelines in difficult natural and climatic conditions, reflects methods for developing trenches, constructing embankments, drilling holes and wells for pile supports, backfilling trenches taking into account the design parameters of pipelines, the specifics of drilling and blasting operations, including including the parallel laying of multi-line highways on different sections of the route.

This joint venture is intended for specialists in construction and design organizations involved in earthworks during the construction of the linear part of pipelines, as well as in the development of projects for the organization of construction and production of works (POS and PPR).

Terminology

Trench - a recess, usually of considerable length and relatively small width, intended for laying the pipeline being laid. A trench as a temporary earthwork is developed in certain parameters depending on the diameter of the pipeline under construction and can be arranged with slopes or with vertical walls.

The dump is usually called the soil laid along the trench during its development by earthmoving machines.

Embankments are earthworks intended for laying pipelines when crossing low or difficult terrain, as well as for building a roadbed along them or softening the route profile when planning a construction strip by means of additional soil filling.

Excavations are earthworks arranged by cutting the soil while softening the longitudinal profile of the route and laying roads along the pipeline construction strip.

Semi-dredging-semi-filling - earthworks, combining the features of cutting and embankment, intended for laying pipelines and roads on steep slopes (mainly transverse slopes).

Ditches - structures in the form of linear recesses, usually arranged to drain the construction strip, they are often called drainage or drainage. Ditches that serve to intercept and divert water flowing from the upstream territory and arranged on the uphill side of the earthen structure are called upland. Ditches that serve to drain water and are located along both boundaries of cuts or roads are called ditches.

Ditches laid during the construction of pipelines (ground method) in swamps along the boundaries of the ROW and used to store water are called fire ditches.

Cavaliers are called embankments, filled out of excess soil formed during the development of recesses, and located along the latter.

Reserves are usually called excavations, the soil from which is used for filling adjacent embankments. The reserve is separated from the embankment slope by a protective berm.

Quarry - a specially developed excavation for the use of soil when filling embankments and located at a considerable distance from them.

Channel - a recess of considerable length and filled with water. Channels are usually arranged during the construction of pipelines in swamps and wetlands and serve as a trench for laying pipelines using the alloy method or as a main channel for a drainage network of a drainage system.

The structural elements of the trench are the profile of the trench, the soil dump, the roller above the trench (after it has been backfilled with soil). The structural elements of the embankment are subgrade, ditches, cavaliers and reserves.

The trench profile, in turn, has the following characteristic elements: bottom, walls, edges.

Embankments have: a base, slopes, a sole and edges of slopes, a ridge.

Bed - a layer of loose, usually sandy soil (10-20 cm thick), poured onto the bottom of the trench in rocky and frozen soils to protect the insulating coating from mechanical damage when laying the pipeline in the trench.

Powder - a layer of soft (sandy) soil, poured over a pipeline laid in a trench (20 cm thick), before filling it with loosened rocky or frozen soil to the design mark of the earth's surface.

The overburden layer of soil is a mineral soft top layer of soil that lies above the continental rocks, which is subject to priority removal (opening) from the construction strip, for the subsequent effective development of rock soil by drilling and blasting.

Boreholes - cylindrical cavities in the soil with a diameter of up to 75 mm and a depth of not more than 5 m, formed by drilling rigs for placing explosive charges when loosening solid soils using the drilling and blasting blasthole method (for constructing trenches).

Wells - cylindrical cavities in the soil with a diameter of more than 76 mm and a depth of more than 5 m, formed by drilling machines for placing explosive charges in them during drilling and blasting operations, both for loosening the soil and blasting for dumping when arranging shelves in mountainous areas.

Integrated sequential method - a method for developing trenches mainly in high-strength permafrost soils for ballasted pipelines with a diameter of 1420 mm, which consists in sequential passage along the trench alignment of several types of rotary trench excavators, or rotary excavators of the same type with different parameters of the working body for constructing a trench of a design profile (up to 3 3m).

Technological gap - the distance along the front between the grips of the production of certain types of work of the technological process of constructing a linear part of the main pipeline within the right of way (for example, a technological gap between preparatory and earthworks, between welding and installation and insulation and laying, and during earthworks in rocky soils gap between teams for overburden, drilling, blasting and excavation of trenches in soils loosened by the explosion).

Operational quality control of work - a continuous technological process of quality control, carried out in parallel with the implementation of any construction and installation operation or process, is carried out in accordance with the technological maps of operational quality control developed for all types of work on the construction of the linear part of the main pipelines.

The technological map of the step-by-step quality control of earthworks reflects the main provisions on the technology and organization of step-by-step control, technological requirements for machines, determines the main processes and operations that are subject to control, controlled indicators that are characteristic of earthworks, the composition and types of control, as well as forms of executive documentation, where the test results are recorded.

1. General Provisions

1.1. The technology of the entire complex of earthworks, including the engineering preparation of the construction strip, in order to comply with the required dimensions and profiles of earthworks, as well as regulated tolerances during earthworks, must be carried out in accordance with the Project, developed taking into account the requirements of current regulatory documents:

¨ "Main pipelines" (SNiP III-42-80);

¨ "Organization of construction production" (SNiP 3.01.01-80);

¨ Earthworks. Bases and Foundations” (SNiP 3.02.01-87);

¨ "Norms of Land Acquisition for Main Pipelines" (SN-452-73) Fundamentals of Land Legislation of the USSR and Union Republics;

¨ “Construction of main pipelines. Technology and Organization” (VSN 004-88, Minneftegazstroy, P, 1989);

¨ RF Law on Environmental Protection;

¨ Technical Rules for blasting on the day surface (M., Nedra, 1972);

¨ Instructions on the technology of blasting in frozen pounds near existing steel underground main pipelines (VSN-2-115-79);

¨ This Code of Rules.

Detailed development of technology and organizational measures is carried out in the preparation of technological maps and projects for the production of works for specific production processes, taking into account the specifics of the relief and soil conditions of each section of the pipeline route.

1.2. Earthworks should be carried out with the provision of quality requirements and with mandatory operational control of all technological processes. It is recommended that all subdivisions for the production of earthworks be provided with step-by-step quality control cards, which are developed in the development of POS and PPR, schemes for integrated mechanization for the construction of main pipelines by design organizations of the industry.

1.3. Excavation work must be carried out in compliance with the Safety Rules, industrial sanitation and the latest achievements in the field of labor protection.

The whole range of earthworks during the construction of pipelines is carried out in accordance with the projects for the organization of construction and work.

1.4. The technology and organization of earthworks should provide for the flow of their production, year-round performance, including on difficult sections of the route, without a significant increase in their labor intensity and cost, while maintaining the specified pace of work. The exception is work on permafrost soils and wetlands of the Far North, where work is recommended to be done only during the period of soil freezing.

1.5. Management and management of labor protection, as well as responsibility for ensuring the conditions for compliance with labor protection requirements in specialized divisions, are recommended to be assigned to managers, chiefs and chief engineers of these organizations. At work sites, the heads of sections (columns), foremen and foremen are responsible for compliance with these requirements.

1.6. Construction machinery and equipment for earthworks must comply with the technical conditions of operation, taking into account the conditions and nature of the work performed; in northern regions with low air temperatures, it is recommended to mainly use machines and equipment in the northern version.

1.7. During the construction of main pipelines, lands provided for temporary use must be brought into line with the requirements of the on-farm land management project of the relevant land users:

· in the production of earthworks, it is not recommended to use techniques and methods that contribute to flushing, blowing and sinking of soils and soils, the growth of ravines, erosion of sands, the formation of mudflows and landslides, salinization, waterlogging of soils and other forms of loss of fertility;

· when draining the right of way by open drainage, discharge of drainage water into sources of water supply for the population, medical water resources, places of recreation and tourism should not be allowed.

2. Production of earthworks. Land reclamation works

2.1. It is recommended to carry out work on the removal and restoration of the layer within the construction strip in accordance with a special land reclamation project.

2.2. The land reclamation project should be developed by design organizations taking into account the specifics of specific sections of the route and be agreed with the land users of these sections.

2.3. Fertile lands are brought into a usable condition, as a rule, in the process of construction work on the pipeline, and if this is not possible, no later than within a year after the completion of the entire complex of works (as agreed with the land user). All work must be completed within the period of land acquisition for construction.

2.4. In the land reclamation project, in accordance with the conditions for the provision of land plots for use and taking into account local natural and climatic features, the following should be determined:

¨ borders of lands along the pipeline route, where reclamation is required;

¨ the thickness of the removed fertile soil layer for each site subject to reclamation;

Rice. Schematic diagram of the right-of-way during the construction of main pipelines

A - the minimum width of the strip in which the fertile soil layer is removed (the width of the trench along the top plus 0.5 m in each direction)

¨ the width of the reclamation zone within the ROW;

¨ the location of the dump for temporary storage of the removed fertile soil layer;

¨ methods of applying a fertile soil layer and restoring its fertility;

¨ permissible excess of the applied fertile soil layer above the level of undisturbed lands;

¨ methods of compaction of loosened mineral soil and fertile layer after backfilling of the pipeline.

2.5. Work on the removal and application of the fertile soil layer (technical reclamation) is carried out by the construction organization; restoration of soil fertility (biological reclamation, including fertilization, sowing of grasses, restoration of moss cover in the northern regions, plowing of fertile soils and other agricultural work) is carried out by land users at the expense of funds provided for by the estimate for reclamation included in the summary construction estimate.

2.6. When developing and agreeing on a land reclamation project for a pipeline laid parallel to an existing gas pipeline, one should take into account its actual position in the plan, the actual depth of occurrence and technical condition, and based on these data, develop design solutions that ensure the safety of the existing pipeline and the safety of work in accordance with "Instructions for the performance of work in the protected zone of main pipelines" and the current safety regulations.

2.7. When laying a pipeline parallel to an existing pipeline, it should be taken into account that the operating organization, before starting work, must mark the location of the axis of the existing pipeline on the ground, identify and mark dangerous places with special warning signs (areas of insufficient deepening and sections of the pipeline that are in poor condition). During the period of work near the existing pipelines or at the intersection with them, the presence of representatives of the operating organization is necessary. As-built documentation for covert work should be drawn up according to the forms given in VSN 012-88, part II.

2.8. The technology of work on the technical reclamation of disturbed lands during the construction of main pipelines consists in removing the fertile soil layer before the start of construction work, transporting it to a temporary storage site and applying it to the restored lands upon completion of construction work.

2.9. In the warm season, the removal of the fertile soil layer and its transfer to the dump should be carried out with a rotary reclamator of the ETR 254-05 type, as well as bulldozers (D-493A, D-694, D-385A, D-522, DZ-27S types) longitudinally transverse passages with a layer thickness of up to 20 cm and transverse passages with a layer thickness of more than 20 cm. With a fertile layer thickness of up to 10 - 15 cm, it is recommended to use motor graders to remove and move it to the dump.

2.10. The removal of the fertile soil layer should be carried out for the entire design thickness of the reclamation layer, if possible, in one pass or in layers in several passes. In all cases, mixing of the fertile soil layer with mineral soil should not be allowed.

Excess mineral soil formed as a result of the displacement of the volume when laying the pipeline into the trench, in accordance with the project, can be evenly distributed and planned on the strip of the removed fertile soil layer (before applying the latter) or taken out of the construction strip to specially designated places.

The removal of excess mineral soil is carried out according to two schemes:

1. After backfilling the trench, the mineral soil is evenly distributed by a bulldozer or motor grader over the strip to be recultivated, then after compaction, the soil is cut with scrapers (D-357M, D-511C, etc.) to the required depth in such a way as to ensure the allowable excess the level of the applied fertile soil layer above the surface of undisturbed lands. The soil is transported by scrapers to the places specially indicated in the project;

2. Mineral soil after leveling and compaction is cut and moved by a bulldozer along the strip and placed in order to increase the efficiency of its loading onto transport in special piles up to 1.5 - 2.0 m high with a volume of up to 150 - 200 m3 from where it is taken by single-bucket excavators (EO type -4225, equipped with a bucket with a straight shovel or grab), or single-bucket front-end loaders (type TO-10, TO-28, TO-18) are loaded into dump trucks and taken out of the construction strip to places specially specified in the project.

2.11. If, at the request of land users, the project also provides for the removal of the fertile soil layer outside the construction strip to special temporary dumps (for example, on especially valuable lands), then its removal and transportation to a distance of up to 0.5 km should be carried out by scrapers (type DZ-1721).

When removing soil over a distance of more than 0.5 km, dump trucks (such as MAZ-503B, KRAZ-256B) or other vehicles should be used.

In this case, it is recommended to load the fertile layer (also pre-shifted into piles) onto dump trucks using front-end loaders (TO-10, D-543 types), as well as single-bucket excavators (EO-4225 type) equipped with a bucket with a front shovel or grab. Payment for all these works should be provided for in the additional estimate.

2.12. The removal of the fertile soil layer, as a rule, is carried out before the onset of stable negative temperatures. In exceptional cases, in agreement with land users and authorities exercising control over land use, it is allowed to remove the fertile soil layer in winter conditions.

When performing work on the removal of the fertile soil layer in the winter season, it is recommended to develop the frozen fertile soil layer with bulldozers (type DZ-27S, DZ-34S, International Harvester TD -25S) with preliminary loosening of it with three-tooth rippers (type DP-26S, DP -9S, U-RK8, U-RKE, International Harvester TD-25S), Caterpillar rippers (model 9B) and others.

Loosening should be carried out to a depth not exceeding the thickness of the removed fertile soil layer.

When loosening the soil with tractor rippers, it is recommended to use a longitudinally rotary technological scheme.

In winter, rotary trench excavators (ETR-253A, ETR-254, ETR-254AM, ETR-254AM-01, ETR-254-05, ETR-307, ETR-309) can be used to remove and move the fertile soil layer in winter.

The immersion depth of the rotor in this case should not exceed the thickness of the removed fertile soil layer.

2.13. Backfilling of the pipeline with mineral soil is carried out at any time of the year immediately after its laying. Rotary trenchers and bulldozers can be used for this.

In the warm season, after filling the pipeline with mineral soil, it is compacted with vibration compactors of the D-679 type, pneumatic rollers or multiple (three to five times) passes of caterpillar tractors over the pipeline filled with mineral soil. The compaction of mineral soil in this way is carried out before filling the pipeline with the transported product.

2.14. In winter, artificial compaction of mineral soil is not carried out. The soil acquires the required density after thawing for three to four months (natural compaction). The compaction process can be accelerated by wetting (soaking) the soil with water in a backfilled trench.

2.15. The application of a fertile soil layer should be carried out only in the warm season (with normal humidity and sufficient bearing capacity of the soil for the passage of cars). For this, bulldozers are used, working in transverse strokes, moving and leveling the fertile soil layer. This method is recommended when the topsoil is over 0.2 m thick.

2.16. If it is necessary to transport the fertile soil layer to the place of application from dumps located outside the construction strip and at a distance of up to 0.5 km from it, scrapers (DZ-1721 type) can be used. With a transportation distance exceeding 0.5 km, the fertile soil layer is delivered using dump trucks, followed by leveling it with bulldozers operating in oblique or longitudinal passages.

Leveling of the fertile soil layer can also be carried out by motor graders (type DZ-122, DZ-98V, equipped in the front with a blade-blade).

Bringing land plots into a suitable condition is carried out in the course of work, and if this is not possible - no later than within a year after completion of work.

2.17. Control over the correctness of the performance of work in accordance with the land reclamation project is carried out by the bodies of state control over the use of land on the basis of a regulation approved by the Government. The transfer of restored lands to land users must be formalized by an act in the prescribed manner.

3. Earthwork under normal conditions

3.1. The technological parameters of earthworks used in the construction of main pipelines (the width, depth and slopes of the trench, the cross section of the embankment and the steepness of its slopes, the parameters of boreholes and wells) are set depending on the diameter of the pipeline being laid, the method of its fixing, the terrain, soil conditions and are determined project. The dimensions of the trench (depth, bottom width, slopes) are set depending on the purpose and external parameters of the pipeline, the type of ballasting, soil characteristics, hydrogeological and terrain conditions.

Specific parameters of earthworks are determined by working drawings.

The depth of the trench is set from the conditions of protecting the pipeline from mechanical damage when vehicles, construction and agricultural vehicles move through it. The depth of the trench when laying main pipelines is taken equal to the diameter of the pipe plus the required amount of backfilling of soil above it and is assigned by the project. At the same time, it must be (according to SNiP 2.05.06-85) not less than:

with a diameter of less than 1000 mm .............................................. ....................................... 0.8 m;

with a diameter of 1000 mm or more .............................................. .................................................. 1.0 m;

· in swamps or peat soils to be drained .................................................. 1.1 m;

· in sand dunes, counting from the lower marks of inter-dune foundations... 1.0 m;

in rocky soils, swampy areas in the absence of travel

motor transport and agricultural machinery .................................................................. ....... 0.6 m.

The minimum width of the trench at the bottom is assigned by SNiP and is taken at least:

¨ D + 300 mm - for pipelines with a diameter of up to 700 mm;

¨ 1.5D - for pipelines with a diameter of 700 mm or more, subject to the following additional requirements:

for pipelines with a diameter of 1200 and 1400 mm when digging trenches with slopes not steeper than 1:0.5, the width of the trench along the bottom can be reduced to a value of D + 500 mm, where D is the nominal diameter of the pipeline.

When excavating soil with earth-moving machines, it is recommended to take the width of the trench equal to the width of the cutting edge of the working body of the machine, adopted by the construction organization project, but not less than that indicated above.

When ballasting the pipeline with weighting loads or fixing it with anchor devices, the width of the trench along the bottom must be taken at least 2.2 D, and for a pipeline with thermal insulation it is established by the project.

It is recommended to take the width of the trench along the bottom in curved sections from forced bending bends equal to twice the width in relation to the width in straight sections.

· a written permit for the right to excavate in the area of ​​underground utilities, issued by the organization responsible for the operation of these utilities;

· a project for the production of earthworks, in the development of which standard technological maps are used;

Work order for the crew of the excavator (if the work is carried out in conjunction with bulldozers and rippers, then for the drivers of these machines) for the production of work.

3.3. Before developing a trench, it is necessary to restore the alignment of the trench axis. When developing a trench with a single-bucket excavator, poles are placed along the axis of the trench in front of the machine and behind along an already dug trench. When digging with a rotary excavator, a vertical sight is installed on the front of it, which allows the driver, focusing on the installed milestones, to keep to the design direction of the route.

3.4. The profile for the trench must be made so that the laid pipeline along the entire length of the lower generatrix is ​​in close contact with the bottom of the trench, and at the turning angles it is located along the line of elastic bending.

3.5. At the bottom of the trench, do not leave fragments of steel, gravel, hard lumps of clay and other objects and materials that can damage the insulation of the pipeline being laid.

3.6. The development of the trench is carried out by single-bucket excavators:

¨ in areas with pronounced hilly terrain (or strongly rugged), interrupted by various (including water) obstacles;

¨ in rocky soils loosened by drilling and blasting;

¨ on sections of curved pipeline inserts;

¨ when working in soft soils with the inclusion of boulders;

¨ in areas of high humidity and swamps;

¨ in watered soils (on rice fields and irrigated lands);

¨ in places where it is impossible or impractical to use bucket-wheel excavators;

¨ in difficult areas specially defined by the project.

To develop wide trenches with slopes (in heavily watered, loose, unstable soils), single-bucket excavators equipped with a dragline are used in the construction of pipelines. Earth-moving machines are equipped with a reliable functioning sound alarm. The signaling system must be familiar to all work crews serving these machines.

In areas with a calm terrain, on gently sloping hills, on soft foothills and on soft, lingering mountain slopes, work can be performed by rotary trench excavators.

3.7. Trenches with vertical walls can be developed without fastening in soils of natural moisture with an undisturbed structure in the absence of groundwater to a depth (m):

· in bulk sandy and gravelly soils......... no more than 1;

· in sandy loam .............................................. ........................ no more than 1.25;

in loams and clays .............................................. ...... no more than 1.5;

in especially dense non-rocky soils ....................... no more than 2.

When developing trenches of great depth, it is necessary to arrange slopes of various positions depending on the composition of the soil and its moisture content (Table).

Table 1

Permissible steepness of slopes of trenches

	The ratio of the height of the slopes to its occurrence at the depth of the excavation, m
Bulk natural moisture
Sandy and gravel wet (unsaturated)
Loam
Loess dry
Rocky on the plain

3.8. In waterlogged, clayey soils with rain, snow (melt) and groundwater, the steepness of the slopes of pits and trenches is reduced compared to that indicated in Table. up to the angle of repose. The manufacturer of works draws up a decrease in the steepness of slopes by an act. Forest-like and bulk soils become unstable when waterlogged, and during their development, wall fastening is used.

3.9. The steepness of the slopes of the trenches for the pipeline and the pits for the installation of pipeline fittings is taken according to the working drawings (in accordance with the table). The steepness of the trench slopes in swamp areas is taken as follows (table):

table 2

The steepness of the trench slopes in swamp areas

3.10. Soil development methods are determined depending on the parameters of the earthwork and the amount of work, the geotechnical characteristics of soils, the classification of soils according to the difficulty of development, local construction conditions, and the availability of earthmoving machines in construction organizations.

3.11. On linear works in the course of digging trenches for pipelines, in accordance with the working drawings, pits are developed for taps, condensate collectors and other technological units with dimensions of 2 m in all directions from the welded joint of the pipeline with fittings.

Under technological breaks (overlaps), pits are developed with a depth of 0.7 m, a length of 2 m and a width of at least 1 m in each direction from the pipe wall.

When constructing the linear part of the pipelines using the in-line method, the soil excavated from the trench is placed in a dump on one (left in the direction of work) side of the trench, leaving the other side free for the movement of vehicles and construction and installation works.

3.12. To prevent the collapse of the excavated soil into the trench, as well as the collapse of the walls of the trench, the base of the excavated soil dump should be located, depending on the state of the soil and weather conditions, but not closer than 0.5 m from the edge of the trench.

Collapsed soil in the trench can be cleared out with a clamshell excavator just before laying the pipeline.

3.13. The development of trenches with a single-bucket excavator with a backhoe is carried out in accordance with the project without the use of manual cleaning of the bottom (this is achieved by a rational distance of the excavator moving and dragging the bucket along the bottom of the trench), which ensures the elimination of scallops at the bottom of the trench.

3.14. The development of trenches by dragline is carried out by frontal or sidewalls. The choice of development method depends on the size of the trenches along the top, the place where the pound is dumped and the working conditions. Wide trenches, especially on swampy and soft soils, are usually developed with side passages, and ordinary trenches with frontal ones.

When constructing trenches, it is recommended to install the excavator from the edge of the face at a distance that ensures the safe operation of the machines (outside the prism of soil collapse): for dragline excavators with a bucket with a capacity of 0.65 m3, the distance from the edge of the trench to the axis of movement of the excavator (for lateral development) should be not less than 2.5 m. On unstable, weak soils, wooden slides are placed under the undercarriage of the excavator or they work from mobile foam sleds.

When developing trenches with single-bucket excavators with a backhoe and a dragline, it is allowed to sort out soil up to 10 cm; soil shortage is not allowed.

3.15. In areas with a high level of standing groundwater, it is recommended to start trenching from lower places to ensure water runoff and drainage of overlying areas.

3.16. To ensure the stability of the walls of the trench when working in unstable soils with rotary excavators, the latter are equipped with special slopes that allow the development of trenches with slopes (steepness of 1: 0.5 or more).

3.17. Trenches, the depth of which exceeds the maximum digging depth of an excavator of this brand, are developed by excavators in combination with bulldozers.

Earthworks in rocky soils in flat terrain and in mountainous conditions

3.18. Earthworks during the construction of main pipelines in rocky soils in flat terrain with slopes up to 8 ° include the following operations and are performed in a certain sequence:

Removing and moving to a dump for storing a fertile layer or opening a layer covering rocky soils;

loosening of rocks by drilling and blasting or mechanically with its subsequent planning;

· development of loosened soils by a single-bucket excavator;

arrangement of a bed of soft soil at the bottom of the trench.

After laying the pipeline in the trench, the following work is performed:

¨ powdering of the pipeline with loosened soft soil;

¨ installation of jumpers in a trench on longitudinal slopes;

¨ backfilling of the pipeline with rocky soil;

¨ reclamation of the fertile layer.

3.19. After removing the fertile layer, to ensure uninterrupted and more productive work of drillers and drilling equipment for loosening rocky soil, the overburden layer is removed until the rock is exposed. In areas with a soft soil layer thickness of 10 - 15 cm or less, it can not be removed.

During roller drilling of charging holes and wells, soft soil is removed only for the purpose of preserving it or using it for laying a bed or powdering a pipeline.

3.20. Works on removal of overburden soil are carried out, as a rule, by bulldozers. If necessary, these works can be performed with single-bucket or rotary excavators, trench fillers, using them both independently and in combination with bulldozers (combined method).

3.21. The removed soil is laid on the trench berm in order to be able to use it for bedding and powdering. A dump of loosened rocky soil is located behind the dump of overburden soil.

3.22. With a small thickness of rocks or in the case of their strong fracturing, loosening is recommended to be carried out with a tractor ripper.

3.23. Loosening of rocky soils is carried out mainly by methods of short-delayed blasting, in which charge wells (holes) are arranged in a square grid.

In exceptional cases of using the instantaneous blasting method (with wide trenches and pits), wells (holes) should be staggered.

3.24. Refinement of the calculated mass of charges and adjustment of the grid location of holes is carried out by test explosions.

3.25. Explosive work must be carried out in such a way that the rock is loosened to the design trench marks (taking into account the construction of a sand bed by 10–20 cm) and re-blasting is not required for its completion.

This equally applies to the device shelves in an explosive way.

When loosening the soil by explosive method, it is also necessary to ensure that pieces of loosened soil do not exceed 2/3 of the size of the excavator bucket intended for its development. Pieces of large sizes are destroyed by overhead charges.

3.26. Before the development of the trench, a rough layout of the loosened rocky soil is carried out.

3.27. When laying the pipeline, in order to protect its insulating coating from mechanical damage about the irregularities present at the bottom of the trench, a bed of soft soil with a thickness of at least 0.1 m is arranged above the protruding parts of the base.

The bed is made from imported or local overburden soft soil.

3.28. For the construction of the bed, mainly rotary trench and single-bucket excavators are used, and in some cases rotary trench fillers, which develop soft overburden located on the strip next to the pipeline trench, near the roadway, and dump it on the bottom of the trench.

3.29. The soil brought by dump trucks and dumped next to the pipe (on the side opposite to the dump from the trench) is placed and leveled at the bottom of the trench using a single-bucket excavator equipped with a dragline, a scraper, a backhoe, or scraper or belt devices. With a sufficient width of the trench (for example, in the areas of ballasting the pipeline or in the sections of the turn of the route), leveling the backfilled soil along the bottom of the trench can be carried out by small-sized bulldozers.

3.30. To protect the insulating coating of the pipeline from damage by pieces of rock, when backfilling over the pipe, it is recommended to arrange a powder of soft overburden or imported soil with a thickness of at least 20 cm above the upper generatrix of the pipe. Powdering of the pipeline is performed by the same technique as backfilling under the pipeline.

In the absence of soft soil, bedding and powdering can be replaced by a continuous lining of wooden slats or straw, reed, foam, rubber and other mats. In addition, bedding can be replaced by laying bags filled with soft soil or sand on the bottom of the trench at a distance of 2–5 m from one another (depending on the diameter of the pipeline) or by installing a foam bed (spraying the solution before laying the pipeline).

3.31. Earthworks during the construction of main pipelines in rocky soils in mountainous areas include the following technological processes:

arrangement of temporary roads and access roads to the highway;

stripping works;

Shelving arrangement;

development of trenches on the shelves;

backfilling of trenches and the design of the roller.

3.32. When the pipeline route passes along steep longitudinal slopes, their planning is carried out by cutting the soil and reducing the angle of elevation. These works are carried out along the entire width of the strip by bulldozers, which, cutting the soil, move from top to bottom and push it to the foot of the slope outside the construction strip. The trench profile is recommended to be placed not in bulk, but in mainland soil. Therefore, the device of the embankment is possible mainly in the area of ​​the passage of transport vehicles.

Shelf arrangement

3.33. When passing tracks along a slope with a transverse steepness of more than 8 °, a shelf should be arranged.

The design and parameters of the shelf are assigned depending on the diameter of the pipes, the dimensions of the trenches and soil dumps, the type of machines used and the methods of work and are determined by the project.

3.34. The stability of a semi-fill-shelf depends on the characteristics of the bulk soil and the soil of the foot of the slope, the steepness of the slope, the width of the bulk part, and the state of the vegetation cover. For the stability of the shelf, it is torn off with a slope of 3 - 4% towards the slope.

3.35. In sections with a transverse slope of up to 15 °, the development of recesses for shelves in non-rocky and loosened rocky soils is carried out by transverse passages of bulldozers perpendicular to the axis of the route. The completion of the shelf and its layout in this case is carried out by longitudinal passages of the bulldozer with layer-by-layer development of the soil and its movement in the semi-fill.

The development of soil when arranging shelves in areas with a transverse slope of up to 15 ° can also be carried out with longitudinal passages of a bulldozer. The bulldozer first cuts and develops the soil at the transition line by half-cuts into a half-fill. After cutting the soil in the first prism at the outer edge of the shelf and moving it to the bulk part of the shelf, the soil of the next prism remote from the boundary of the transition to the semi-fill (towards the inner part of the shelf) is developed, and then in the next prisms located in the mainland soil - until the profile of the half-cut is fully developed .

For large volumes of earthworks, two bulldozers are used, which are developing the shelf from both sides with longitudinal passages towards each other.

3.36. In areas with a transverse slope of more than 15 °, single-bucket excavators equipped with a front shovel are used to develop loose or non-rocky soil when arranging shelves. The excavator develops the soil within the semi-excavation and pours it into the bulk part of the shelf. During the initial development of the shelf, it is recommended to anchor it with a bulldozer or tractor. The final finishing and layout of the shelf is carried out by bulldozers.

3.37. When arranging shelves and digging trenches in mountainous areas for loosening non-separable rocks, it is possible to use tractor rippers or a drilling and blasting method of development.

3.38. When operating a tractor ripper, it is taken into account that the efficiency of its work increases if the direction of the working stroke is taken from top to bottom downhill and loosening is carried out with the choice of the longest working stroke.

3.39. Methods for drilling boreholes and wells, as well as methods for loading and detonating charges when arranging shelves in mountainous areas and trenches on shelves, are similar to the methods used when developing trenches in rocky soils on flat terrain.

3.40. It is recommended to carry out excavation work on the development of trenches on the shelves ahead of the removal of pipes to the route.

Trenches on shelves in soft soils and heavily weathered rocks are developed by single-bucket and bucket-wheel excavators without loosening. In areas with dense rocky soils, before developing a trench, the soil is loosened by drilling and blasting.

Earth-moving machines in trenching move along a carefully planned shelf; at the same time, single-bucket excavators move in the same way as when constructing trenches in rocky soils on flat terrain, along a deck of metal or wooden shields.

3.41. The dump of soil from the trench is placed, as a rule, at the edge of the slope of the half-ditch on the right side of the shelf along the development of the trench. If the soil dump is located in the travel zone, then for the normal operation of construction machines and mechanisms, the soil is planned along the shelf and rammed with bulldozers.

3.42. On sections of the route with longitudinal slopes up to 15 °, the development of trenches, if there are no transverse slopes, is carried out by single-bucket excavators without special preliminary measures. When working on longitudinal slopes from 15 to 36°, the excavator is pre-anchored. The number of anchors and the method of their fastening is determined by the calculation, which should be part of the project for the production of works.

When working on longitudinal slopes of more than 10 °, to determine the stability of the excavator, it is checked for spontaneous shift (sliding) and, if necessary, anchoring is performed. Tractors, bulldozers, winches are used as anchors on steep slopes. The holding devices are located at the top of the slope on horizontal platforms and connected to the excavator with a cable.

3.43. On longitudinal slopes up to 22 °, excavation with a single-bucket excavator is allowed in the direction both from the bottom up and from the top down the slope.

In areas with a slope of more than 22 °, to ensure the stability of single-bucket excavators, it is allowed: with a straight shovel, work only in the direction from top to bottom along the slope with the bucket forward in the course of work, and with a backhoe - only from top down along the slope, with the bucket back in the course of work.

The development of trenches on longitudinal slopes up to 36 ° in soils that do not require loosening is carried out by single-bucket or rotary excavators, in previously loosened soils - by single-bucket excavators.

The operation of rotary excavators is allowed on longitudinal slopes up to 36 ° when moving them from top to bottom. With slopes from 36 to 45 °, their anchoring is used.

The work of single-bucket excavators with a longitudinal slope of over 22 ° and bucket-wheel excavators over 45 ° is carried out by special methods according to the project for the production of works.

The development of a trench by bulldozers is carried out on longitudinal slopes up to 36 °.

The construction of trenches on steep slopes from 36 ° and above can also be carried out using a tray method using scraper installations or bulldozers.

Backfilling trenches in the mountains

3.44. Backfilling of a pipeline laid in a trench on shelves and on longitudinal slopes is carried out similarly to backfilling in rocky soils on flat terrain, i.e. with a preliminary arrangement of the bed and the powdering of the pipeline with soft soil or the replacement of these operations with a lining. Lining can be made of polymeric roll materials, foamed polymers, concrete. It is forbidden to use rotting materials for lining (reed mats, wooden slats, logging waste, etc.).

If the soil of the dump is planned along the shelf, then the final backfilling of the pipeline with rocky soil is carried out by a bulldozer or a rotary trencher, the remaining soil is leveled along the construction strip. In the event that the soil is located at the edge on the side of the slope of the half-ditch, then single-bucket excavators, as well as front-end bucket loaders, are used for these purposes.

3.45. The final backfilling of the pipeline on longitudinal slopes is carried out, as a rule, by a bulldozer, which moves along or at an angle to the trench, and can also be carried out from top to bottom along the slope by a trencher with its obligatory anchoring on slopes over 15 °. On slopes greater than 30° in places where the use of mechanisms is not possible, backfilling can be done manually.

3.46. For backfilling of the pipeline laid in trenches developed by the tray method on steep slopes with the soil dump located at the bottom of the slope, scraper trench-fillers or scraper winches are used.

3.47. To prevent washing away of the soil when backfilling the pipeline on steep longitudinal slopes (over 15 °), it is recommended to install jumpers.

Features of earthworks in winter conditions

3.48. Excavation work in winter is associated with a number of difficulties. The main ones are soil freezing to different depths and the presence of snow cover.

When predicting soil freezing to a depth of more than 0.4 m, it is advisable to protect the soil from freezing, in particular, by loosening the soil with single or multi-point rippers.

3.49. In some places of a small area, it is possible to protect the soil from freezing by warming it with wood residues, sawdust, peat, applying a layer of foam styrene, as well as non-woven rolled synthetic materials.

3.50. To reduce the duration of thawing of frozen soil and in order to maximize the use of the fleet of earth-moving machines in warm weather, it is recommended to remove snow from the strip of the future trench during the period when positive temperatures are established.

Trench development in winter

3.51. In order to avoid the trenches being covered with snow and freezing of the soil dump during work in winter, the pace of trench development should correspond to the pace of insulation and laying work. The technological gap between the earthmoving and insulating-laying columns is recommended to be no more than two-day productivity of the earthmoving column.

Methods for developing trenches in winter are prescribed depending on the time of excavation, the characteristics of the soil and the depth of its freezing. The choice of a technological scheme for earthworks in winter should provide for the preservation of snow cover on the soil surface until the start of trenching.

3.52. With a soil freezing depth of up to 0.4 m, trenching is carried out as under normal conditions: a rotary or single-bucket excavator equipped with a backhoe bucket with a bucket capacity of 0.65 - 1.5 m3.

3.53. With a soil freezing depth of more than 0.3 - 0.4 m, before working it out with a single-bucket excavator, the soil is loosened mechanically or by drilling and blasting.

3.54. When using the drilling and blasting method for loosening frozen soils, work on the development of trenches is carried out in a certain sequence.

The trench strip is divided into three grips:

¨ zone of work on drilling holes, charging them and blasting;

¨ zone of planning works;

¨ area for the development of loosened soil by an excavator.

The distance between the grippers should ensure the safe conduct of work on each of them.

Borehole drilling is carried out by motor augers, perforators and self-propelled drilling machines.

3.55. When developing frozen soil using tractor rippers with a capacity of 250 - 300 hp. trench development work is carried out according to the following schemes:

1. With a soil freezing depth of up to 0.8 m, the soil is loosened with a rack-mounted ripper to the entire freezing depth, and then it is developed with a single-bucket excavator. Excavation of loosened soil in order to avoid refreezing must be carried out immediately after loosening.

2. With a freezing depth of up to 1 m, work can be carried out in the following sequence:

loosen the soil with a rack-mounted ripper in several passes, then select it with a bulldozer along the trench;

The remaining soil, having a freezing thickness of less than 0.4 m, is developed with a single-bucket excavator.

A trough-shaped trench in which the excavator operates is arranged with a depth of no more than 0.9 m (for an EO-4121 type excavator) or 1 m (for an E-652 excavator or similar foreign excavators) to ensure that the rear of the excavator rotates when unloading the bucket.

3. With a freezing depth of up to 1.5 m, work can be carried out similarly to the previous scheme, with the difference that the soil in the trough must be loosened with a rack ripper before the passage of the excavator.

3.56. The development of trenches in solid frozen and permafrost soils with a freezing depth of the active layer of more than 1 m can be carried out by a complex combined sequential method, i.e. the passage of two or three different types of bucket wheel excavators.

First, a trench of a smaller profile is developed, and then it is increased to design parameters using more powerful excavators.

In complex sequential work, you can use either different brands of bucket-wheel excavators (for example, ETR-204, ETR-223, and then ETR-253A or ETR-254) or excavators of the same model equipped with working bodies of different sizes (for example, ETR-309).

Before the passage of the first excavator, the soil is loosened, if necessary, by a heavy tractor ripper.

3.57. For the development of frozen and other dense soils, buckets of bucket-wheel excavators must be equipped with teeth hardened with wear-resistant overlays or reinforced with hard-alloy plates.

3.58. With a significant thawing depth (more than 1 m), the soil can be developed with two rotary excavators. At the same time, the first excavator develops the top layer of thawed soil, and the second - the layer of frozen soil, laying it behind the thawed soil dump. For the development of water-saturated soil, you can also use a single-bucket excavator equipped with a backhoe.

3.59. During the period of the greatest thawing of the frozen layer (at a thawing depth of 2 m or more), the trench is developed by conventional methods, as in ordinary or marshy soils.

3.60. Before laying the pipeline in a trench, the base of which has uneven frozen ground, a bed 10 cm high is made of thawed loose or finely loosened frozen soil at the bottom of the trench.

3.61. When thawing frozen soil (30 - 40 cm) for subsequent loosening of the frozen layer, it is advisable to first remove it with a bulldozer or a shovel excavator, and then work according to the same schemes as for frozen soils.

Pipeline backfilling

3.62. To protect the insulating coating of the pipeline laid in the trench, backfilling is carried out with loosened soil. If the backfill soil on the parapet is frozen, then it is advisable to powder the laid pipeline to a height of at least 0.2 m from the top of the pipe with imported soft thawed or loosened mechanically or by drilling and blasting frozen soil. Further backfilling of the pipeline with frozen soil is carried out by bulldozers or rotary trench fillers.

Earthworks in swamps and wetlands

3.63. A swamp (from a construction point of view) is an excessively moistened area of ​​the earth's surface, covered with a layer of peat with a thickness of 0.5 m or more.

Areas with significant water saturation with a peat deposit thickness of less than 0.5 m are classified as wetlands.

Areas that are covered with water and do not have peat cover are waterlogged.

3.64. Depending on the patency of construction equipment and the complexity of construction and installation work during the construction of pipelines, swamps are classified into three types:

First- swamps completely filled with peat, allowing the operation and repeated movement of marsh equipment with a specific pressure of 0.02 - 0.03 MPa (0.2 - 0.3 kgf / cm2) or the operation of conventional equipment using shields, sleighs, or temporary roads , providing a decrease in the specific pressure on the surface of the deposit to 0.02 MPa (0.2 kgf/cm2).

Second- swamps completely filled with peat, allowing the work and movement of construction equipment only on shields, sledges or temporary technological roads, providing a decrease in the specific pressure on the surface of the deposit to 0.01 MPa (0.1 kgf / cm2).

Third- swamps filled with spreading peat and water with a floating peat crust (alloy) and without an alga, allowing the operation of special equipment on pontoons or conventional equipment from floating facilities.

Development of trenches for underground pipeline laying in swamps

3.65. Depending on the type of swamp, the method of laying, the time of construction and the equipment used, the following schemes for conducting earthmoving operations in swampy areas are distinguished:

¨ trenches with preliminary excavation;

¨ development of trenches using special equipment, shields or slates, which reduce the specific pressure on the soil surface;

¨ development of trenches in winter;

¨ development of trenches by explosion.

Construction on swamps should be started after a thorough examination of it.

3.66. The development of trenches with preliminary excavation is used when the depth of the peat layer is up to 1 m with an underlying base having a high bearing capacity. The preliminary removal of peat to the mineral soil is carried out by a bulldozer or an excavator. The width of the excavation formed in this case should ensure the normal operation of the excavator moving along the surface of the mineral soil and developing the trench to its full depth. The trench is arranged with a depth of 0.15 - 0.2 m below the design level, taking into account the possible slippage of the slopes of the trench in the period from the moment of development to the laying of the pipeline. When using an excavator for peat removal, the length of the created front of work is assumed to be 40 - 50 m.

3.67. The development of trenches using special equipment, shields or slates, which reduce the specific pressure on the soil surface, is used in swampy areas with a peat deposit thickness of more than 1 m and having a low bearing capacity.

To develop trenches in soft soils, swamp excavators equipped with a backhoe or dragline should be used.

The excavator can also develop a trench while on foam sledges, which move through the swamp with the help of a winch and are located on mineral soil. Instead of a winch, one or two tractors can be used.

3.68. Excavation of trenches in the summer should be ahead of pipeline insulation if carried out in the field. The lead time depends on the characteristics of pounds and should not exceed 3 - 5 days.

3.69. The feasibility of laying pipelines through long swamps in the summer should be justified by technical and economic calculations and determined by the construction organization project.

Deep and long swamps with a low bearing capacity of the peat cover should be passed in winter, and shallow small marshes and wetlands in the summer season.

3.70. In winter, as a result of soil freezing to the full (design) depth of trench development, the bearing capacity of the soil increases significantly, which makes it possible to use conventional earth-moving equipment (rotary and single-bucket excavators) without the use of sledges.

In areas with deep freezing of peat, work should be carried out in a combined way: loosening the frozen layer by drilling and blasting and excavating the soil to the design mark with a single-bucket excavator.

3.71. The development of trenches in swamps of all types, especially in difficult swamps, is advisable to carry out in an explosive way. This method is economically justified in cases where it is very difficult to carry out work from the surface of the swamp, even using special equipment.

3.72. Depending on the type of swamp and the size of the required trench, various options for developing them by explosive methods are used.

In open and lightly forested swamps, when developing canals 3–3.5 m deep, up to 15 m wide at the top, and the peat layer thickness up to 2/3 of the trench depth, elongated cord charges are used from waste pyroxylin gunpowder or waterproof ammonites.

When laying a pipeline in deep swamps covered with forests, it is advisable to develop trenches up to 5 m deep with concentrated charges placed along the axis of the trench. In this case, there is no need for preliminary clearing of the route from the forest. Concentrated charges are placed in charging funnels, formed, in turn, by small borehole or concentrated charges. For this, waterproof ammonites are usually used in cartridges with a diameter of up to 46 mm. The depth of the charging funnel is taken taking into account the location of the center of the main concentrated charge at 0.3 - 0.5 of the channel depth.

When developing trenches up to 2.5 m deep and 6-8 m wide at the top, it is effective to use borehole charges from waterproof explosives. This method can be used on swamps of types I and II both with and without forest. Wells (vertical or inclined) are located along the axis of the trench at a calculated distance from each other in one or two rows, depending on the design width of the trench bottom. The diameter of the wells is 150 - 200 mm. Inclined wells at an angle of 45 - 60 ° to the horizon are used when it is necessary to eject the soil on one side of the trench.

3.73. The choice of explosives, the mass of the charge, the depth, the location of the charges in the plan, the methods of blasting, as well as the organizational and technical preparation for the production of drilling and blasting operations and the testing of explosive materials are set out in the "Technical Rules for Explosive Operations on the Day Surface" and in the "Methodology for calculating explosive parameters during construction of canals and trenches in swamps” (M., VNIIST, 1970).

Backfilling of the pipeline in swamps

3.74. Methods for performing work when backfilling trenches in swamps in the summer depend on the type and structure of the swamps.

3.75. In swamps of types I and II, backfilling is carried out either by swamp bulldozers, when the movement of such machines is ensured, or by dragline excavators on a widened or normal course, moving along the sledges on dumps of soil, previously planned by two passages of the bulldozer.

3.76. The excess soil obtained during backfilling is placed in an over-trench roller, the height of which is determined taking into account the draft. If there is not enough soil for backfilling the trench, it should be developed by an excavator from lateral reserves, which should be laid from the axis of the trench at a distance of at least three of its depths.

3.77. In deep swamps with a fluid consistency of peat, inclusions of sapropelite or covering with drifts (type III swamps), after laying the pipeline on a solid base, it can not be covered.

3.78. Backfilling of trenches in swamps in winter is carried out, as a rule, by bulldozers on widened caterpillars.

Surface laying of the pipeline in the embankment

3.79. The method of erecting embankments is determined by the conditions of construction and the type of earthmoving machines used.

Soil for filling the embankment in flooded areas and in swamps is being developed in nearby quarries located on elevated places. The soil in such quarries is usually more mineralized and therefore more suitable for a stable embankment.

3.80. The development of soil in quarries is carried out by scrapers or single-bucket or rotary excavators with simultaneous loading into dump trucks.

3.81. In floating bogs, when filling the embankment, the floating crust (alloy) of small thickness (no more than 1 m) is not removed, but immersed to the bottom. In this case, if the thickness of the crust is less than 0.5 m, the filling of the embankment directly onto the raft is carried out without the device of longitudinal slots in the raft.

With a raft thickness of more than 0.5 m, longitudinal slots can be arranged in the raft, the distance between which should be equal to the base of the future earth embankment below.

3.82. The slitting should be done by blasting. Powerful rafts before the start of backfilling are destroyed by explosions of small charges laid in a checkerboard pattern on a strip equal to the width of the earthen strip below.

3.83. Embankments through swamps with low bearing capacity are constructed from imported soil with preliminary peat removal at the base. In swamps with a bearing capacity of 0.025 MPa (0.25 kgf / cm2) and more, embankments can be poured without peat directly on the surface or along brushwood lining. In bogs of type III, embankments are dumped mainly on the mineral bottom due to the extrusion of the peat mass by the soil mass.

3.84. It is recommended to build embankments with excavation in swamps with a peat cover thickness of not more than 2 m. The expediency of peat removal is determined by the project.

3.85. In swamps and other watered areas that have water runoff across the embankment, the filling is carried out from well-draining coarse-grained and gravelly sands, gravel, or special culverts are arranged.

· the first layer (25 - 30 cm high above the swamp), delivered by dump trucks, is covered by the pioneer method of sliding. The soil is unloaded at the edge of the swamp, and then pushed towards the embankment by a bulldozer. Depending on the length of the swamp and the conditions of the entrance, the embankment is erected from one or both banks of the swamp;

· the second layer (up to the design mark of the bottom of the pipe) is poured in layers with compaction immediately along the entire length of the transition;

· the third layer (up to the design level of the embankment) is backfilled after the pipeline is laid.

The leveling of the soil along the embankment is carried out by a bulldozer, backfilling of the laid pipeline is carried out by single-bucket excavators.

3.87. Embankments are poured during the construction process, taking into account the subsequent sedimentation of the soil; the amount of settlement is set by the project depending on the type of soil.

3.88. Backfilling of embankments with preliminary removal of peat at the base is carried out in a pioneering way from the “head”, and without peat removal both from the head part and from the plank road located along the axis of the pipeline.

Earthworks in the construction of concreted or ballasted pipelines

3.89. Earthworks for the construction of a pipeline ballasted with reinforced concrete weights or a concreted pipeline are characterized by increased volumes of work and can be performed both in summer and in winter.

3.90. With the underground method of laying a concreted trench gas pipeline, it is necessary to develop the following parameters:

¨ trench depth - comply with the project and be at least Dn + 0.5 m (Dn - outer diameter of the concreted gas pipeline, m);

¨ the width of the trench along the bottom in the presence of slopes of 1: 1 or more - not less than Dn + 0.5 m.

When developing a trench for alloying a pipeline, its width along the bottom is recommended to be at least 1.5 Dn.

3.91. The minimum gap between the load and the trench wall when ballasting the gas pipeline with reinforced concrete weighting loads should be at least 100 mm, or the width of the trench along the bottom when ballasting with loads or fixing with anchor devices is recommended to be at least 2.2 Dn.

3.92. In view of the fact that pipelines concreted or ballasted with reinforced concrete loads are laid in swamps, swampy and watered areas, earthwork methods are similar to earthworks in swamps (depending on the type of swamps and season).

3.93. To develop trenches for pipelines of large diameters (1220, 1420 mm), concreted or ballasted with reinforced concrete loads, the following method can be used: a bucket-wheel excavator in the first pass opens a trench with a width equal to about half the required trench width, then the soil is returned to its place by a bulldozer; then, with the second pass of the excavator, the soil is selected on the remaining unloosened part of the trench and again returned to the trench by a bulldozer. After that, the loosened soil for the entire profile is selected by a single-bucket excavator.

3.94. When laying a pipeline in areas of predicted flooding, ballasted with reinforced concrete weights, in winter conditions, the method of group installation of weights on the pipeline can be used. In this regard, the trench can be developed in the usual way, and widening it for a group of goods can be done only in certain areas.

Earthworks in this case are carried out as follows: a rotary or single-bucket (depending on the depth and strength of the frozen soil) excavator opens a trench of the usual (for a given diameter) width; then the sections of the trench where the cargo groups are to be installed are covered with soil. In these places, on the sides of the developed trench, holes are drilled for explosive charges in one row, so that after blasting the total width of the trench in these places would be sufficient to install weighting loads. Then the soil, loosened by the explosion, is removed by a single-bucket excavator.

3.95. The backfilling of a pipeline that is concreted or ballasted with weights is carried out using the same methods as when backfilling a pipeline in swamps or frozen soils (depending on the conditions of the route and the time of year).

Peculiarities of excavation technology when laying gas pipelines with a diameter of 1420 mm in permafrost soils

3.96. The choice of technological schemes for arranging trenches in permafrost soils is carried out taking into account the depth of soil freezing, its strength characteristics and the time it takes to complete the work.

3.97. The construction of trenches in the autumn-winter period with a freezing depth of the active layer from 0.4 to 0.8 m using single-bucket excavators of the EO-4123, ND-150 types is carried out after preliminary loosening of the soil with rack rippers of the D-355, D-354 type and others , which loosen the soil to the entire freezing depth in one technological step.

With a freezing depth of up to 1 m, loosening it is carried out by the same rippers in two passes.

With a greater freezing depth, the development of trenches with single-bucket excavators is carried out after preliminary loosening of the soil by drilling and blasting. Boreholes and wells along the trench strip are drilled using drilling machines such as BM-253, MBSH-321, Kato and others in one or two rows, which are charged with explosives and explode. With a freezing depth of the active layer of soil up to 1.5 m, loosening it for the development of trenches, especially those located no further than 10 m from existing structures, is carried out using the borehole method; with a depth of soil freezing more than 1.5 m - by the borehole method.

3.98. When arranging trenches in permafrost soils in winter with their freezing to the entire depth of development, both in swamps and in other conditions, it is advisable to use mainly rotary trench excavators. Depending on the strength of the developed soil, the following technological schemes are used for trenching:

in permafrost soils with a strength of up to 30 MPa (300 kgf / cm2), trenches are developed in one technological step by bucket-wheel excavators of the ETR-254, ETR-253A, ETR-254A6 ETR-254AM, ETR-254-05 types with a bottom width of 2.1 m and maximum depth up to 2.5 m; ETR-254-S - bottom width 2.1 m and depth up to 3 m; ETR-307 or ETR-309 - bottom width 3.1 m and depth up to 3.1 m.

If it is necessary to develop trenches of greater depth (for example, for ballasted gas pipelines with a diameter of 1420 mm), the same excavators, using tractor rippers and bulldozers of the D-355A or D-455A type, develop a trough-shaped excavation 6–7 m wide and up to 0.8 m deep ( depending on the required design depth of the trench), then in this recess, using the appropriate types of bucket-wheel excavators for a given diameter of the pipeline, a trench of the design profile is developed in one technological pass.

in permafrost soils with a strength of up to 40 MPa (400 kgf/cm2), the development of wide-profile trenches for laying loadable pipelines with a diameter of 1420 mm with reinforced concrete weights of the UBO type in areas with a depth of 2.2 to 2.5 m and a width of 3 m is carried out by a rotary trench excavator of the ETR type -307 (ETR-309) in one pass, or by a complex-combined and sequential method.

The development of trenches in such areas by the in-line complex-combined method, first, along the border of one side of the trench, a pioneer trench is developed by a rotary trench excavator of the ETR-254-01 type with a working body width of 1.2 m, which is filled with a bulldozer of the D-355A, D-455A or DZ type -27C. Then, at a distance of 0.6 m from it, a second trench 1.2 m wide is developed by a rotary excavator of the ETR-254-01 type, which is also covered with loosened soil using the same bulldozers. The final development of the design profile of the trench is carried out by a single-bucket excavator of the ND-1500 type, which, simultaneously with the selection of the soil of the pioneer trenches loosened by rotary excavators, also develops the soil pillar between them.

A variant of this scheme in areas of soil with a strength of up to 25 MPa (250 kgf / cm2) can be the use of bucket-wheel excavators of the ETR-241 or 253A type instead of ETR-254-01 for extracting the second pioneer trench. In this case, there are practically no works on the development of the rear sight.

when developing trenches of such parameters in permafrost soils with a strength of 40 to 50 MPa (from 400 to 500 kgf / cm2), the complex of earth-moving machines (according to the previous scheme) additionally includes tractor rack rippers of the D-355, D-455 type for preliminary loosening the top most durable soil to a depth of 0.5 - 0.6 m before the operation of bucket-wheel excavators.

For the development of trenches in soils of higher strength - over 50 MPa (500 kgf / cm2), when loosening and excavation of the soil pillar with a single-bucket excavator is of great difficulty, it is necessary to loosen it by drilling and blasting before the operation of single-bucket excavators. To do this, drilling machines such as BM-253, BM-254 drill a series of holes in the body of the pillar at intervals of 1.5 - 2.0 m to a depth exceeding the design depth of the trench by 10 - 15 cm, which are charged with explosive charges for loosening and explode. After that, excavators of the ND-1500 type excavate all the loosened soil until the design profile of the trench is obtained.

· trenches for pipelines loaded with reinforced concrete weights (UBO type) with a depth of 2.5 to 3.1 m are developed in a certain technological sequence.

In areas with soil strength up to 40 MPa (400 kgf / cm2) and more, at first, tractor rack rippers based on D-355A or D-455A loosen the upper permafrost soil layer on a strip 6–7 m wide to a depth of 0.2–0, 7 m depending on the required final trench depth. After removing the loosened soil with bulldozers in the resulting trough-shaped excavation with a rotary trench excavator of the ETR-254-01 type, a pioneer cut-trench 1.2 m wide is developed along the border of the project trench. After filling this slot with excavated loosened soil, at a distance of 0.6 m from the edge the second pioneer trench is cut by another rotary excavator of the ETR-254-01 type, which is also filled with the help of bulldozers of the D-355, D-455 type. Then, with a single-bucket excavator of the ND-1500 type, a trench of the full design profile is developed simultaneously with the soil of the pillar.

· in areas of heavily icy high-strength permafrost soils with a cutting resistance of more than 50 - 60 MPa (500 - 600 kgf / cm2), trenching should be carried out with preliminary loosening of soils by drilling and blasting. At the same time, depending on the required depth of trenches, drilling of holes in a checkerboard pattern in 2 rows using machines of the BM-253, BM-254 type should be carried out in a trough-shaped recess with a depth of 0.2 (with a trench depth of 2.2 m) to 1.1 m (at a depth of 3.1 m). To eliminate the need for work on the arrangement of a trough-shaped excavation, it is advisable to introduce drilling machines of the MBSH-321 type.

3.99. On sections of the route in permafrost, low-icy soils, where gas pipelines are to be ballasted with mineral soil using NCM devices, it is recommended to take the following trench parameters: bottom width no more than 2.1 m, depth depending on the amount of backfill and the presence of a heat-insulating screen - from 2.4 up to 3.1 m.

The development of trenches in such areas up to 2.5 m deep in soils with a strength of 30 MPa (300 kgf / cm2) is recommended to be carried out on a full profile with rotary trench excavators of the ETR-253A or ETR-254 type. Trenches up to 3 m deep in such soils can be developed by rotary excavators of the ETR-254-02 and ETR-309 types.

In soils with a strength of more than 30 MPa (300 kgf/cm2), mechanized earth-moving complexes for the implementation of the technological scheme described above should additionally include tractor-mounted rippers of the D-355A or D-455A type for preliminary loosening of the most durable upper layer of permafrost soil to a depth of 0 .5 - 0.6 m before the development of the trench profile by rotary excavators of the indicated brands.

In areas with soil strength up to 40 MPa (400 kgf / cm2), it is also possible to use a technological scheme with sequential excavation and development of a trench profile along the axis of the route by two rotary excavators: first ETR-254-01 with a rotor width of 1.2 m, and then ETR -253A, ETR-254 or ETR-254-02, depending on the required trench depth in this area.

For the effective development of wide trenches of ballasted gas pipelines with a diameter of 1420 mm in solid permafrost soils, a sequential-complex method is recommended with two powerful rotary trench excavators of the ETR-309 type (with different parameters of the working body), in which the first excavator equipped with interchangeable unified working bodies with a width of 1.2 ¸ 1.5 and 1.8 ¸ 2.1 m, first cuts a pioneer trench ~ 1.5 m wide, and then the second excavator, equipped with two mounted side rotary cutters, moving sequentially, finalizes it to the design dimensions of 3x3 m required to accommodate the pipeline with ballasting devices.

In soils with a strength of more than 35 MPa (350 kgf/cm2), it is necessary to include preliminary loosening of the upper frozen layer of soil to a depth of 0.5 m using tractor-mounted rippers of the D-355A or D-455A type in the specified sequentially combined technological scheme.

3.100. In areas with the occurrence of especially strong permafrost soils with a strength of 50 MPa or more (500 kgf / cm2), it is recommended to develop trenches with such parameters with single-bucket excavators of the ND-1500 type with preliminary loosening of the frozen layer by drilling and blasting. To drill holes to full depth (up to 2.5 - 3.0 m), it is necessary to use drilling machines such as BM-254 and MBSH-321.

3.101. In all cases, when performing excavation work on trenching in these soil conditions in the summer, in the presence of a thawed top layer of soil, it is removed from the trench strip using bulldozers, after which the trenching work is carried out according to the technological schemes given above, taking into account the design profile of the trench and the strength of the permafrost in this area.

When the top layer of soil thaws, in the event of its transition to a plastic or fluid state, which makes it difficult to conduct earthworks for loosening and developing the underlying permafrost soil, this layer of soil is removed by a bulldozer or a shovel excavator, and then the permafrost soil, depending on its strength, is developed by the above methods.

Embankments on permafrost soils, as a rule, should be built from imported soil mined in quarries. In this case, it is not recommended to take soil for an embankment on the gas pipeline construction site.

A quarry should be arranged (if possible) in loose-frozen soils, since a change in their temperature slightly affects their mechanical strength.

In the process of erection, the embankment must be backfilled, taking into account its subsequent settlement. The increase in its height in this case is set: when performing work in the warm season and filling the embankment with mineral soil - by 15%, when performing work in the winter and filling the embankment with frozen soil - by 30%.

3.102. Backfilling of a pipeline laid in a trench made in permafrost soils is carried out as under normal conditions, if after laying the pipeline immediately after the development of the trench and backfilling (if necessary), the soil of the dump was not subjected to freezing. In the event of freezing of the soil of the dump, in order to avoid damage to the insulating coating of the pipeline, it must be sprinkled with imported thawed fine-grained soil or finely loosened frozen soil to a height of at least 0.2 m from the top of the pipe.

Further backfilling of the pipeline is carried out with a pound of dump using a bulldozer or, preferably, a rotary trencher, which is capable of developing a dump with freezing to a depth of 0.5 m. If the dump is frozen deeper, it must first be loosened mechanically or by drilling and blasting. When backfilling with frozen soil, a soil bead is arranged above the pipeline, taking into account its settlement after thawing.

Drilling of wells and installation of piles for above-ground laying of pipelines

3.103. The method of erecting pile foundations is prescribed depending on the following factors:

¨ permafrost conditions of the route;

¨ time of year;

¨ technology of work performance and results of technical and economic calculations.

Pile foundations in the construction of pipelines in areas of permafrost are usually built from prefabricated piles.

3.104. The construction of pile foundations is carried out depending on the soil conditions in the following ways:

driving piles directly into the plastic-frozen soil or into previously developed leader holes (drilling method);

installation of piles in pre-thawed soil;

installation of piles in pre-drilled and filled with a special solution wells;

installation of piles using a combination of the above methods.

Driving piles into the frozen mass can only be carried out in high-temperature plastic-frozen soils with a temperature above -1 °C. It is recommended to drive piles into such soils with a content of coarse and solid inclusions up to 30% after drilling leader wells, which are formed by immersing special leader pipes (with a cutting edge at the bottom and a hole in the lateral upper part). The leader hole diameter is 50 mm less than the smallest size of the pile cross-section.

3.105. The technological sequence of operations for installing piles in previously developed leader wells is as follows:

¨ the pile driving mechanism clogs the leader to the design mark;

¨ the leader with the core is retrieved by the winch of the excavator, which moves with the leader pipe to the next well, where the whole process is repeated;

¨ the pile is driven into the formed leader hole by the second pile driving mechanism.

3.106. If there are coarse-grained inclusions in the soil (more than 40%), it is not advisable to use leader drilling, since the initial force to extract the leader increases significantly and the core is shedding back into the well.

3.107. In heavy clays and loams, the use of bored piles is also impractical due to the fact that the core in the pipe is wedged and is not forced out of the leader.

Leader wells can be arranged by drilling by thermomechanical, shock-rope or other methods.

3.108. In cases where it is impossible to use bored piles, they are immersed in wells previously drilled by thermomechanical, mechanical or shock-rope drilling machines.

The technological sequence of operations when drilling wells with percussion-rope drilling machines is as follows:

arrange a platform for installing the unit, which must be strictly horizontal. This is especially important when drilling wells on slopes, where the layout of the site for installing the unit and for smooth entry to it is carried out by a bulldozer by raking up snow and watering it with water (for freezing the upper layer); in the summer, the site is planned by a bulldozer;

· a well is drilled with a diameter of 50 mm larger than the largest transverse dimension of the pile;

The well is filled with a sandy-clay mortar heated to 30 - 40 ° C in the volume of approximately 1/3 of the well, based on the complete filling of the space between the pile and the wall of the well (the solution is prepared directly on the track in mobile boilers using drill cuttings with the addition of fine-grained sand in the amount 20 - 40% of the volume of the mixture; it is desirable to deliver gelling water to hot mobile containers or heat it during the work process);

Install the pile in the well with a pipelayer of any brand.

When the pile is driven to the design mark, the solution should be squeezed out to the surface of the earth, which serves as evidence of the complete filling of the space between the walls of the well and the surface of the pile with the solution. The process of drilling a well and driving a pile into a drilled well should not last more than 3 days. in winter and more than 3-4 hours in summer.

3.109. The technology of drilling wells and installing piles using thermomechanical drilling machines is set out in the "Instructions on the technology of drilling wells and installing piles in frozen soils using thermomechanical drilling machines" (VSN 2-87-77, Minneftegazstroy).

3.110. The duration of the process of freezing piles with permafrost soil depends on the season of work, characteristics of frozen soil, soil temperature, pile design, composition of sand-clay mortar and other factors and should be specified in the work design.

Trench backfill

3.111. Before starting work on backfilling the pipeline in any soil, it is necessary:

¨ check the design position of the pipeline;

¨ check the quality and, if necessary, repair the insulating coating;

¨ to carry out the work envisaged by the project to protect the insulating coating from mechanical damage (planning the bottom of the trench, laying the bed, powdering the pipeline with loose soil);

¨ arrange entrances for the delivery and maintenance of the excavator and bulldozer;

¨ obtain written permission from the customer to backfill the laid pipeline;

¨ issue a work order for the production of work to the driver of a bulldozer or trench filler (or the crew of a shovel excavator, if backfilling is performed by an excavator).

3.113. When backfilling the pipeline in rocky and frozen soils, the safety of pipes and insulation from mechanical damage is ensured by powdering over the laid pipeline from soft (thawed) sandy soil to a thickness of 20 cm above the upper generatrix of the pipe, or by installing protective coatings provided by the project.

3.114. Backfilling of the pipeline under normal conditions is carried out mainly by bulldozers and rotary-type trench fillers.

3.115. Backfilling of the pipeline by bulldozers is carried out: straight, oblique parallel, oblique and combined passages. In the cramped conditions of the construction strip, as well as in places with a reduced right of way, work is carried out with oblique parallel and oblique cross passages by a bulldozer or a rotary trench filler.

3.116. If there are horizontal curves on the pipeline, the curved section is first filled up, and then the rest. Moreover, backfilling of a curved section begins from its middle, moving alternately towards its ends.

3.117. In areas of terrain with vertical curves of the pipeline (in ravines, beams, on hills, etc.), backfilling is carried out from top to bottom.

3.118. With large volumes of backfilling, it is advisable to use trench fillers in combination with bulldozers. At the same time, at first, the backfill is carried out with a trench filler, which during the first pass has maximum productivity, and then the remaining part of the dump is shifted into the trench by bulldozers.

3.119. Backfilling of a pipeline laid in a trench with a dragline is carried out in cases where the operation of equipment in the area of ​​​​the dump is impossible, or at large distances of backfilling with soil. In this case, the excavator is located on the side of the trench opposite the dump, and the soil for backfilling is taken from the dump and poured into the trench.

3.120. After backfilling on non-reclaimed lands above the pipeline, a soil roller is arranged in the form of a regular prism. The height of the roller should match the amount of possible soil settlement in the trench.

On recultivated lands in the warm season, after the pipeline is backfilled with mineral soil, it is compacted with pneumatic rollers or caterpillar tractors by multiple passes (three to five times) over the backfilled pipeline. The compaction of mineral soil in this way is carried out before filling the pipeline with the transported product.

4. Quality control and acceptance of earthworks

4.1. The quality control of earthworks consists in the systematic monitoring and verification of the compliance of the work performed with the design documentation, the requirements of the joint venture in compliance with the tolerances (given in Table ), as well as technological maps as part of the PPR.

Table 3

Permits for the production of earthworks

4.2. The purpose of control is to prevent the occurrence of marriage and defects in the process of work, to exclude the possibility of accumulation of defects, to increase the responsibility of performers.

4.3. Depending on the nature of the operation (process) being performed, operational quality control is carried out directly by performers, foremen, foremen or a special representative-controller of the customer's company.

4.4. Defects identified during the control, deviations from the designs, requirements of the SP, PPR or technological standards for maps should be corrected before the start of subsequent operations (works).

4.5. Operational quality control of earthworks includes:

¨ verification of the correctness of the transfer of the actual axis of the trench with the design position;

¨ verification of marks and lane width for the operation of bucket-wheel excavators (in accordance with the requirements of the project for the production of works);

¨ checking the profile of the bottom of the trench with measuring its depth and design marks, checking the width of the trench along the bottom;

¨ checking the slopes of trenches depending on the structure of the soil specified in the project;

¨ checking the thickness of the backfill layer at the bottom of the trench and the thickness of the pipeline powder layer with soft soil;

¨ control of the thickness of the layer of backfill and dike of the pipeline;

¨ checking the marks of the top of the embankment, its width and the steepness of the slopes;

¨ the size of the actual radii of curvature of the trenches in the sections of horizontal curves.

4.6. The width of trenches along the bottom, including those in sections ballasted with reinforced concrete weights or screw anchor devices, as well as in sections of curves, is controlled by templates lowered into the trench. The strip marks for the operation of rotary excavators are controlled by a level.

The distance from the center line to the trench wall along the bottom in dry sections of the route should be at least half the design width of the trench, this value should not be exceeded by more than 200 mm; in flooded and swampy areas - more than 400 mm.

4.7. The actual turning radius of the trench in plan is determined by the theodolite (the deviation of the actual axis of the trench in a straight section cannot exceed ± 200 mm).

4.8. Compliance of the trench bottom marks with the design profile is checked using geometric leveling. The actual elevation of the trench bottom is determined at all points where the design elevations are indicated in the working drawings, but at least 100, 50 and 25 m - respectively for pipelines with a diameter of up to 300, 820 and 1020 - 1420 mm. The actual elevation of the trench bottom at any point should not exceed the design one and may be less than it by up to 100 mm.

4.9. In the case when the project provides for adding loose soil to the bottom of the trench, the thickness of the leveling layer of loose soil is controlled by a probe lowered from the trench berm. The thickness of the leveling layer must be at least the design; tolerance for layer thickness is given in table. .

4.10. If the project provides for powdering the pipeline with soft soil, then the thickness of the layer of powder laid in the trench of the pipeline is controlled by a measuring ruler. The thickness of the powder layer is at least 200 mm. Allowed deviation of the layer thickness within the limits specified in table. .

4.11. The marks of the recultivated strip are controlled by geometric leveling. The actual elevation of such a strip is determined at all points where the design elevation is indicated in the land reclamation project. The actual mark must be at least the design mark and not exceed it by more than 100 mm.

4.12. On non-reclaimed lands, using a template, the height of the roller is controlled, which must be at least the design height and not exceed it by more than 200 mm.

4.13. When laying an aboveground pipeline in an embankment, its width is controlled by a tape measure, the width of the embankment on top should be 1.5 diameters of the pipeline, but not less than 1.5 m and exceed it by no more than 200 mm. The distance from the axis of the pipeline is controlled by a tape measure. The slope of the embankment is controlled by the template.

Reducing the transverse dimensions of the embankment against the design one is allowed by no more than 5%, with the exception of the thickness of the soil layer above the pipeline in sections of convex curves, where a decrease in the backfill layer above the pipeline is not allowed.

4.14. In order to be able to carry out complex work, it is necessary to control the shifting pace of trench development, which must correspond to the shifting pace of insulation and laying work, and in case of factory insulation, the pace of insulating pipe joints and laying the finished pipeline into the trench. Backward trenching is generally not allowed.

4.15. Acceptance of completed earthworks is carried out upon commissioning of the entire pipeline. Upon delivery of completed objects, the construction organization (general contractor) is obliged to transfer to the customer all technical documentation, which should contain:

working drawings with the changes made to them (if any) and a document on the execution of the changes made;

Intermediate acts for hidden work;

drawings of earthworks made according to individual projects in difficult construction conditions;

a list of imperfections that do not interfere with the operation of an earthen structure, indicating the timing of their elimination (in accordance with the agreement and contract between the contractor and the customer);

· a list of permanent benchmarks, geodetic signs and route layout indicators.

4.16. The procedure for acceptance and delivery of completed works, as well as the execution of documentation, must be carried out in accordance with the current rules for the acceptance of works.

4.17. For underground and above-ground laying, the pipeline throughout its entire length must rest on the bottom of the trench or the bed of the embankment.

The correctness of the arrangement of the foundation for the pipeline and its laying (the bottom of the trench along the length, the depth of laying, the support of the pipeline along the entire length, the quality of the filling of the bed from soft soil) must be checked by the construction organization and the customer on the basis of geodetic control before filling the pipeline with soil with the preparation of the corresponding act.

4.18. Particular attention in earthworks is paid to the preparation of the base - a bed for pipelines of large diameters, in particular 1420 mm, the acceptance of which must be carried out using leveling surveys throughout the pipeline.

4.19. Delivery and acceptance of main pipelines, including earthworks, is formalized by special acts.

5. Environmental protection

5.1. The performance of work during the construction of main pipelines should be carried out taking into account the requirements for environmental protection established by federal and republican laws, building codes and rules, including:

¨ Fundamentals of land legislation of the USSR and the Union republics;

¨ Law on the Protection of Atmospheric Air;

¨ Law on the Protection of the Aquatic Environment;

¨ Departmental building codes “Construction of main pipelines. Technology and Organization” (VSN 004-88, Minneftegazstroy. M., 1989);

¨ "Instructions for the performance of construction work in the protected areas of the main pipelines of the Mingazprom" (VSN-51-1-80, M, 1982), as well as these provisions.

5.2. The most significant changes in the natural environment in permafrost areas can occur as a result of a violation of the natural heat exchange of soils with the atmosphere and a sharp change in the water and thermal regime of these soils, which occurs as a result of:

· damage to the moss and vegetation cover along the route and the area adjacent to it;

clearing of forest vegetation;

Disruption of the natural regime of snow deposits.

The combined effect of these factors can significantly increase the adverse effect on the thermal regime of permafrost, especially heavily icy subsiding soils, which can lead to changes in the overall environmental situation over a wide area.

In order to avoid these unpleasant consequences, it is necessary:

¨ earthworks on subsiding soils should be carried out mainly during the period of stable negative air temperatures with the presence of snow cover;

¨ traffic in a snowless period is recommended only within the roadway, the movement of heavy wheeled and caterpillar vehicles outside the road is not allowed;

¨ all construction work on the route is carried out in the shortest possible time;

¨ the preparation of the territory allotted for the construction of pipelines in such areas is recommended to be carried out according to the technology that allows the maximum preservation of the vegetation cover on it;

¨ after completion of work on backfilling the pipeline in certain sections, immediately carry out land reclamation, removal of construction debris and residual materials, without waiting for the commissioning of the entire pipeline;

¨ all damage to the vegetation cover on the construction strip at the end of work should be immediately covered with fast-growing grass that takes root well in these climatic conditions.

5.3. When performing work, any activity leading to the formation of new lakes or the drainage of existing reservoirs, a significant change in the natural drainage of the territory, a change in the hydraulics of streams or the destruction of significant sections of river beds is not recommended.

When performing any work, exclude the possibility of backwater and surface water in areas located outside the right of way. If it is impossible to fulfill this requirement, water passes should be arranged in the soil dumps, including special culverts (siphons).

5.4. When excavating trenches for pipelines, land should be stored in two separate dumps. The upper sod layer is laid in the first dump, and the rest of the soil is laid in the second. After laying the pipeline in the trench, the soil returns to the trench strip in the reverse order with layer-by-layer compaction. Excess soil from the second dump is recommended to be removed to low relief places in such a way as not to disturb the natural drainage regime of the territory.

6. Safety in earthworks

6.1. It is necessary for the technical personnel of construction organizations to ensure that the workers comply with the Safety Rules provided for by the current documents:

6.3. All workers on the track must be familiar with the warning signs used in the production of earthworks.

6.4. Manufacturing enterprises are required to take measures to ensure fire safety and industrial sanitation.

6.5. Places of work, transport and construction machines must be provided with first aid kits with a set of hemostatic, dressings and other means necessary for first aid. Employees must be familiar with the rules for providing first aid.

6.6. Water for drinking and cooking in order to avoid gastrointestinal diseases is recommended to be used on the basis of the conclusion of the local sanitary and epidemiological station only from sources suitable for this purpose. Drinking water must be boiled.

6.7. When performing work in the northern regions of the country in the spring and summer, it is recommended that all workers be provided with protective (Pavlovsky nets, closed overalls) and repellents (dimethyl phthalate, diethyltoluamide, etc.) against mosquitoes, midges, horseflies, midges and instruct on the procedure for using these means . When working in areas where the encephalitis tick is spread, all workers must be given anti-encephalitis vaccinations.

6.8. In winter, special attention should be paid to the implementation of measures to prevent frostbite, including the creation of heating points. Workers should be trained in first aid for frostbite.

Approved by Order

Ministry of Regional Development of Russia

Set of rules

EARTH STRUCTURES, BASES AND FOUNDATIONS

UPDATED VERSION OF SNiP 3.02.01-87

Earthworks, Grounds and Footings

SP 45.13330.2012

Introduction date

Foreword

The goals and principles of standardization in the Russian Federation are established by the Federal Law of December 27, 2002 N 184-FZ "On Technical Regulation", and the development rules - by the Decree of the Government of the Russian Federation of November 19, 2008 N 858 "On the Procedure for the Development and Approval of Codes of Rules".

About the set of rules

1. Performers - Research, Design and Survey and Design and Technology Institute of Foundations and Underground Structures. N.M. Gersevanova (NIIOSP) - Institute of OAO "Research Center "Construction".

2. Introduced by the Technical Committee for Standardization TC 465 "Construction".

3. Prepared for approval by the Department of Architecture, Construction and Urban Policy.

4. Approved by the Order of the Ministry of Regional Development of the Russian Federation (Ministry of Regional Development of Russia) on December 29, 2011 N 635/2 and entered into force on January 1, 2013.

5. Registered by the Federal Agency for Technical Regulation and Metrology (Rosstandart). Revision 45.13330.2010 "SNiP 3.02.01-87. Earthworks, bases and foundations".

Information about changes to this set of rules is published in the annually published information index "National Standards", and the text of changes and amendments - in the monthly published information indexes "National Standards". In case of revision (replacement) or cancellation of this set of rules, a corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notification and texts are also posted in the public information system - on the official website of the developer (Ministry of Regional Development of Russia) on the Internet.

Introduction

This set of rules contains instructions for the production and conformity assessment of earthworks, the construction of foundations and foundations in the construction of new buildings and structures, reconstruction. The set of rules was developed in the development of SP 22.13330 and SP 24.13330.

Updating and harmonization of SNiP was carried out on the basis of scientific research carried out in recent years in the field of foundation engineering, domestic and foreign experience in the application of advanced technologies in construction production and new means of mechanization of construction and installation works, new building materials.

SNiP 3.02.01-87 was updated by NIIOSP named after V.I. N.M. Gersevanova - by the Institute of JSC "Research Center "Construction" (Doctor of Engineering Sciences V.P. Petrukhin, Candidate of Engineering Sciences O.A. Shulyatiev - leaders of the topic; Doctors of Engineering Sciences: B.V. Bakholdin, P.A. Konovalov, N. S. Nikiforova, V. I. Sheinin, Candidates of Technical Sciences: V. A. Barvashov, V. G. Budanov, H. A. Dzhantimirov, A. M. Dzagov, F. F. Zekhniev, M. N. Ibragimov, V. K. Kogai, I. V. Kolybin, V. N. Korolkov, G. I. Makarov, S. A. Rytov, A. N. Skachko, P. I. Yastrebov; engineers: A. B. Meshchansky, O. A. Mozgacheva).

“SP 45.13330.2012. Set of rules. Earthworks, foundations and foundations. Updated version of SNiP 3.02.01-87 (approved by Order of the Ministry of Regional Development of Russia dated December 29, 2011 N 635/2) Document ... "

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"SP 45.13330.2012. Code of rules. Ground

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Updated edition of SNiP

(approved by Order of the Ministry of Regional Development of Russia dated

12/29/2011 N 635/2)

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"SP 45.13330.2012. Code of Practice. Earthworks,

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SNiP 3.02.

(approved by Order of the Ministry of Regional Development of Russia of December 29, 2011 N 635/2) Approved by Order of the Ministry of Regional Development of Russia of December 29, 2011 N 635/2 CODE OF RULES

EARTH STRUCTURES, BASES AND FOUNDATIONS

UPDATED VERSION SNiP 3.02.

01-87 Earthworks, Grounds and Footings SP 45.13330.2012 Date of introduction January 1, 2013 Preface Government of the Russian Federation dated November 19, 2008 N 858 "On the procedure for the development and approval of sets of rules."

About the set of rules

1. Performers - Research, Design and Survey and Design and Technology Institute of Foundations and Underground Structures. N.M. Gersevanova (NIIOSP) - Institute of OAO "Research Center "Construction".

2. Introduced by the Technical Committee for Standardization TC 465 "Construction".

3. Prepared for approval by the Department of Architecture, Construction and Urban Policy.

4. Approved by the Order of the Ministry of Regional Development of the Russian Federation (Ministry of Regional Development of Russia) on December 29, 2011 N 635/2 and entered into force on January 1, 2013.

5. Registered by the Federal Agency for Technical Regulation and Metrology (Rosstandart). Revision 45.13330.2010 "SNiP 3.02.01-87. Earthworks, bases and foundations".

Information about changes to this set of rules is published in the annually published information index "National Standards", and the text of changes and amendments - in the monthly published information indexes "National Standards". In case of revision (replacement) or cancellation of this set of rules, a corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notification and texts are also posted in the public information system - on the official website of the developer (Ministry of Regional Development of Russia) on the Internet.

Introduction

This set of rules contains instructions for the production and conformity assessment of earthworks, the construction of foundations and foundations in the construction of new buildings and structures, reconstruction. The set of rules was developed in the development of SP 22.13330 and SP 24.13330.

Updating and harmonization of SNiP was carried out on the basis of scientific research carried out in recent years in the field of foundation engineering, domestic and foreign experience in the application of advanced technologies in construction production and new mechanization tools.

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construction and installation works, new building materials.

Update SNiP 3.02.

01-87 performed by NIIOSP named after V.I. N.M. Gersevanova - by the Institute of JSC "Research Center "Construction" (Doctor of Technical Sciences V.P. Petrukhin, Candidate of Technical Sciences O.A. Shulyatyev - leaders of the topic;

doctor of tech. Sciences: B.V. Bakholdin, P.A. Konovalov, N.S. Nikiforova, V.I. Sheinin; tech candidates. Sciences:

V.A. Barvashov, V.G. Budanov, Kh.A. Dzhantimirov, A.M. Dzagov, F.F. Zekhniev, M.N. Ibragimov, V.K. Kogay, I.V. Kolybin, V.N. Korolkov, G.I. Makarov, S.A. Rytov, A.N. Skachko, P.I. Hawks; engineers: A.B.

Meshchansky, O.A. Mozgachev).

1 area of ​​use

This set of rules applies to the production and acceptance of: earthworks, arrangement of bases and foundations in the construction of new, reconstruction and expansion of buildings and structures.

These rules should be observed when arranging earthworks, bases and foundations, drawing up projects for the production of works (PPR) and organizing construction (POS).

When carrying out excavation work, arranging bases and foundations for hydraulic structures, water transport structures, reclamation systems, main pipelines, roads and railways and airfields, communication and power lines, as well as cable lines for other purposes, in addition to the requirements of these rules, the requirements of the relevant sets of rules that take into account the specifics of the construction of these structures.

This set of rules uses references to the following regulatory documents:

SP 22.13330.2011 "SNiP 2.02.01-83*. Foundations of buildings and structures" SP 24.13330.2011 "SNiP 2.02.03-85. Pile foundations" SP 28.13330.2012 "SNiP 2.03.11-85. Corrosion protection of building structures "SP 34.13330.2012 "SNiP 2.05.02-85*. Highways" SP 39.13330.2012 "SNiP 2.06.05-84*. Dams made of soil materials" SP 47.13330.2012 "SNiP 11-02-96. Engineering surveys for construction" ConsultantPlus: note.

Apparently, there was a typo in the official text of the document: the correct number is SP 48.13330.2011, not SP 48.13330.2012.

SP 48.13330.2012 "SNiP 12-01-2004. Organization of construction" SP 70.13330.2012 "SNiP 3.03.01-87. Bearing and enclosing structures" SP 71.13330.2012 "SNiP 3.04.01-87. Insulating and finishing coatings" SP 75.13330.2012 "SNiP 3.05.05-84. Technological equipment and pipelines" SP 81.13330.2012 "SNiP 3.07.03-85*. Reclamation systems and facilities" SP 86.13330.2012 "SNiP III-42-80*. Main pipelines "SP 116.13330.2012 "SNiP 22-02-2003. Engineering protection of territories, buildings and structures from dangerous geological processes. Basic provisions" SP 126.13330.2012 "SNiP 3.01.03-84. Geodetic works in construction" SP 129.13330.2012 SNiP 3.05.04-85. External networks and water supply and sewerage facilities" SNiP 3.07.02-87. Hydraulic marine and river transport facilities SNiP 12-03-2001. Labor safety in construction. Part 1. General requirements of SNiP 12-04-2002. Labor safety in construction. Part 2. Construction production GOST 9.602-2005. Unified system of protection against corrosion and aging. Underground structures. General requirements for corrosion protection GOST 12.1.004-91. System of labor safety standards. Fire safety. Are common

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requirements of GOST 17.4.3.02-85. Protection of Nature. Soils. Requirements for the protection of the fertile soil layer during earthworks GOST 17.5.3.05-84. Protection of Nature. Land reclamation. General requirements for grounding GOST 17.5.3.06-85. Protection of Nature. Earth. Requirements for determining the norms for the removal of the fertile soil layer in the production of earthworks GOST 10060.0-95. Concrete. Methods for determining frost resistance. General requirements GOST 10180-90. Concrete. Methods for determining strength according to control samples GOST 10181-2000. Concrete mixes. Test methods GOST 12536-79. Soils. Methods for laboratory determination of granulometric (grain) and microaggregate composition GOST 12730.5-84. Concrete. Methods for determining water resistance GOST 16504-81. The system of state testing of products. Testing and quality control of products. Basic terms and definitions GOST 18105-86*. Concrete. Strength control rules GOST 18321-73. Statistical quality control. Methods for random sampling of piece products GOST 19912-2001. Soils. Methods of field tests by static and dynamic sounding GOST 22733-2002. Soils. Method for laboratory determination of maximum density GOST 23061-90. Soils. Methods for radioisotope measurements of density and humidity GOST 23732-79. Water for concretes and mortars. Specifications GOST 25100-2011*. Soils. Classification GOST 25584-90. Soils. Methods for laboratory determination of the filtration coefficient GOST 5180-84. Soils. Methods for laboratory determination of physical characteristics GOST 5686-94. Soils. Field test methods for piles GOST 5781-82. Hot-rolled steel for reinforcing reinforced concrete structures. Specifications.

Note. When using this set of rules, it is advisable to check the effect of reference standards and classifiers in the public information system - on the official website of the national body of the Russian Federation for standardization on the Internet or according to the annually published information index "National Standards", which was published as of January 1 of the current year , and according to the corresponding monthly published information signs published in the current year. If the referenced document is replaced (modified), then when using this set of rules, one should be guided by the replaced (modified) document. If the referenced document is canceled without replacement, then the appendix in which the reference to it is given applies in the part that does not affect this reference.

3. Terms and definitions

3.1. Barreta: load-bearing element of a reinforced concrete foundation, carried out using the "wall in the ground" method.

3.2. Temporary anchor: ground anchor with a design life of no more than two years.

3.3. Slurry Yield: The volume of slurry with a given effective viscosity obtained from 1 ton of slurry.

3.4. VPT: a method of placing concrete in a trench or borehole using a vertically movable concrete casting pipe.

3.5. Geosynthetics: geotextile materials in the form of rolls, bags, geogrids, reinforcing bars made from glass fiber, synthetic, basalt or carbon fiber.

3.6. Ground anchor: a geotechnical structure designed to transfer axial pull-out loads from the structure being fixed to the bearing soil layers only within the root part of its length and consisting of 3 parts: head, free part and root.

3.7. Hydraulic fracturing: a method of strengthening soils associated with the injection of a solution (water) into the well,

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with the subsequent formation of an artificial local crack in the soil mass, filled with a solution.

3.8. Ground dowels: geotechnical structure for stability of slopes and slopes, arranged horizontally or obliquely without additional tension.

3.9. Trench capture: a fragment of a trench developed for subsequent concreting or filling with prefabricated elements with monolithic.

3.10. Injection zone: a limited interval in a well or injector through which a solution (water) is injected into the soil.

3.11. Retrievable anchor: a ground anchor (temporary) whose design allows its thrust to be fully or partially retrieved (on the free length of the anchor).

3.12. Ultrasonic control: an ultrasonic method for quality control (continuity) of bored piles in a construction site.

3.13. Anchor Root: The part of the anchor that transfers the load from the anchor's thrust to the ground.

3.14. Clogging, plugging: filling of pores and cracks in the soil with solid particles of the injected solution that prevent filtration.

3.15. Compensatory injection: a method of maintaining or restoring the initial stress-strain state (SSS) of the foundation soils of existing objects during a number of geotechnical works (tunneling, pitting and other buried structures) by injecting hardening solutions into the soil through wells (injectors) located between the object geotechnical works and adjacent protected objects.

3.16. Collar injection: a method of pumping a fixing solution into the soil through wells equipped with collar columns or injectors, which make it possible to treat zones (intervals) in the soil mass repeatedly and in any sequence.

3.17. Load-bearing buried wall: A buried wall intended to be used as a load-bearing member of a permanent structure.

3.18. Dumps: massifs of soil arranged by hydraulic filling, without additional leveling and compaction.

3.19. Failure during grouting: reducing the flow rate of the solution absorbed by the soil to the minimum allowable value at a given pressure (failure pressure).

3.20. Anchor head: an integral element of the anchor that transfers the load from the fixed element of the structure or soil to the anchor rod.

3.21. Buried boundary wall: Dirt wall intended for use only as a temporary enclosure for a construction excavation (excavation).

3.22. Sinus: The cavity between the soil and the surface of a structure or the outer surfaces of adjacent structures (for example, the cavity between an excavation enclosure and a foundation being erected).

3.23. Continuity check: a method for quality control (continuity) of bored piles under construction site conditions.

3.24. Permanent anchor: ground anchor with a design life equal to the service life of the retained structure.

3.25. Wall section: A constituent element of a reinforced concrete wall separated by concreting restraints (butt structures).

3.26. Suspension (water): a mixture of water and solid particles (cement, clay, fly ash, ground sand and other substances) with a predominant size of 0.1 microns.

3.27. Anchor rod: the part of the anchor that transfers the load from the head to the root.

3.28. Buried trench wall: An underground wall constructed in a trench under a thixotropic clay (or other) mortar, followed by filling the trench with in-situ reinforced concrete or precast elements.

3.29. Grouting slurry: A binder-based hardening aqueous slurry used for fixing non-cohesive soils, compacting voids and fractured rock.

3.30. Cementation: changing the physical and mechanical properties of soils with the help of cement mortars injected into the soil using technologies: injection, jet or drilling mixing.

3.31. Discharge-pulse technology (electric discharge technology): technology for the installation of geotechnical structures (bored injection and bored piles, ground anchors, dowels),

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based on the treatment of the side surface and the heel of the well with shock waves arising from pulsed high-voltage discharges in a moving concrete mixture.

3.32. Stacks: correctly stacked and layer-by-layer compacted soil massifs that serve as the foundation of railways and roads, dam barriers and hydraulic structures, building materials and soils, etc.

4. General provisions

4.1. This set of rules is based on the following assumptions and provides that:

the development of a project for the production of works (PPR) and a construction organization project (POS) must be carried out by specialists with the appropriate qualifications and experience;

coordination and communication between specialists in engineering surveys, design and construction should be ensured;

Appropriate quality control must be ensured in the production of building products and the performance of work at the construction site;

construction work must be carried out by qualified and experienced personnel who meet the requirements of standards and specifications;

maintenance of the structure and associated engineering systems should ensure its safety and working condition for the entire period of operation;

the structure must be used for its intended purpose in accordance with the project.

4.2. When carrying out excavation work, arranging foundations and foundations, the requirements of the codes of practice for the organization of construction production, geodetic work, safety precautions, fire safety rules in the production of construction and installation work should be observed.

4.3. Earthworks, foundations and foundations must comply with the project and be carried out in accordance with the project for the production of works.

4.4. When conducting blasting operations, the requirements of the uniform safety rules for blasting operations should be observed.

4.5. When developing quarries, it is necessary to comply with the requirements of uniform safety rules for the development of mineral deposits in an open way.

4.6. Soils, materials, products and structures used in the construction of earthworks, foundations and foundations must meet the requirements of projects and relevant standards. Replacement of the soils, materials, products and structures provided for by the project, which are part of the structure under construction or its foundation, is allowed only upon agreement with the design organization and the customer.

4.7. When performing work on the construction of foundations from monolithic, prefabricated concrete or reinforced concrete, stone or brickwork, on bases prepared in accordance with the requirements of these rules, SP 70.13330 and SP 71.13330 should be followed.

4.8. During earthworks, foundations and foundations, incoming, operational and acceptance control should be carried out, guided by the requirements of SP 48.13330.

4.9. Acceptance of earthworks, foundations and foundations with the drawing up of certificates of examination of hidden works should be carried out, guided by Appendix B. If necessary, it is allowed to indicate in the project other elements that are subject to intermediate acceptance with the preparation of certificates of examination of hidden works.

4.10. In projects, it is allowed, with appropriate justification, to designate methods of work performance and technical solutions, to establish maximum deviations, volumes and methods of control that differ from those provided for by these rules.

4.11. The need for monitoring, its scope and methodology are established in accordance with SP 22.13330.

4.12. Earthworks, foundations and foundations consistently include the following steps:

a) preparatory;

b) pilot production (if necessary);

c) production of basic works;

d) quality control;

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5.1. The rules of this section apply to the performance of works on artificial lowering of the groundwater level (hereinafter referred to as dewatering) at newly constructed or reconstructed facilities, as well as on the removal of surface water from the construction site.

The choice of method of dewatering should take into account the natural environment, the size of the drained area, the methods of construction work in the pit and near it, their duration, the impact on nearby buildings and utilities, and other local construction conditions.

5.2. To protect pits and trenches from groundwater, various methods are used, which include borehole water intake, wellpoint method, drainage, beam water intake and open drainage.

5.3. Open (connected to the atmosphere) wells, depending on the task and engineering and geological conditions of the construction site, can be water intake (gravitational and vacuum), self-draining, absorbing, unloading (to reduce the piezometric pressure in the soil mass), waste (when draining water into an underground working ).

Open gravity wells can be effectively used in permeable soils with a filtration coefficient of at least 2 m/day with a required drawdown depth of more than 4 m. Basically, such wells are equipped with submersible electric pumps operating under the bay.

In low-permeable soils (clayed or silty sands) with a filtration coefficient of 0.2 to 2 m/day, vacuum water wells are used, in the cavity of which a vacuum develops with the help of pumping units of wellpoint systems for vacuum dewatering, which ensures an increase in the water-holding capacity of the wells. Typically, one such unit can serve up to six wells.

5.4. The wellpoint method, depending on the parameters of the drained soils, the required depth of lowering and the design features of the equipment, is divided into:

wellpoint method of gravitational dewatering, used in permeable soils with a filtration coefficient from 2 to 50 m/day, in non-stratified soils with a decrease in one step to 4

5 m (greater value in less permeable soils);

wellpoint method of vacuum dewatering, used in low-permeability soils with a filtration coefficient from 2 to 0.2 m/day with a decrease in one step of 5 - 7 m; if necessary, the method, with less efficiency, can be applied in soils with a filtration coefficient of up to 5 m/day;

wellpoint ejector method of dewatering, used in low-permeability soils with a filtration coefficient from 2 to 0.2 m / day at a depth of lowering the groundwater level up to 10 - 12 m, and with a certain justification - up to 20 m.

5.5. Drainages for construction purposes can be linear or reservoir with the inclusion of the last linear type drainage in the design.

Linear drainages carry out drainage of soils by withdrawing groundwater using perforated pipes with sand and gravel (crushed stone) sprinkling with the withdrawal of selected waters to sumps equipped with submersible pumps. Effective drainage depth by linear drains

Up to 4 - 5 m.

Linear drains can be arranged inside the pit, at the base of the slopes of earthworks, in the areas surrounding the construction site.

Reservoir drainages are provided for the withdrawal of groundwater during the construction period from the entire area of ​​the pit. This type of drainage is arranged when groundwater is withdrawn in soils with a filtration coefficient of less than 2 m / day, as well as in cases of flooded fractured rocky base.

When groundwater is withdrawn from silty or clayey soils, the reservoir drainage design provides for two layers: the lower one is made of coarse sand 150–200 mm thick and the upper one is made of

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gravel or crushed stone 200 - 250 mm thick. If in the future it is planned to operate the reservoir drainage as a permanent structure, then the thickness of its layers should be increased.

When sampling groundwater from rocky soils, in the cracks of which there is no sandy-argillaceous filler, reservoir drainage can consist of one gravel (crushed stone) layer.

The withdrawal of groundwater taken by reservoir drainage is carried out into a linear drainage system, the sand and gravel dressing of which is mated with the reservoir drainage body.

5.6. Open drainage is used for temporary drainage of the surface layer of soil in pits and trenches. Shallow drainage ditches can be both open and filled with filter material (crushed stone, gravel). The groundwater captured by the grooves is discharged into sumps equipped with submersible pumps.

5.7. Prior to the start of work on dewatering, it is necessary to examine the technical condition of buildings and structures located in the zone of influence of the work, as well as clarify the location of existing underground utilities, assess the impact on them of lowering the groundwater level (GWL) and, if necessary, provide for protective measures.

5.8. Dewatering wells equipped with submersible pumps are the most common types of dewatering systems and can be used in a wide variety of hydrogeological conditions. The depths of the wells are determined depending on the depth and thickness of the aquifer, the filtration characteristics of the rocks, and the required level of groundwater level decrease.

5.9. Drilling of dewatering wells, depending on the hydrogeological conditions, can be carried out with direct or reverse flushing or by the shock-rope method. Drilling wells with clay flushing is not allowed.

5.10. Installation of filter columns in dewatering wells is carried out in compliance with the following requirements:

a) before installing the filter column in the percussion-rope drilling method, the bottom of the well should be thoroughly cleaned by pouring clean water into it and gelling until completely clarified; during rotary drilling with direct and reverse flushing, the well is pumped or washed with a mud pump;

b) when installing the filter, it is necessary to make sure of the strength and tightness of the connections of its lowered links, the presence of guide lights and a plug of the column sump on the column;

c) when drilling wells, it is necessary to take samples to clarify the boundaries of aquifers and the granulometric composition of soils.

5.11. To increase the water-holding capacity of wells and wellpoints in water-saturated soils with a filtration coefficient of less than 5 m / day, as well as in coarse-grained or fractured soils with fine aggregate, sand and gravel (or crushed stone) sprinkling with a particle size of 0.5 - 5 should be arranged in the filter zone mm.

When water is taken from fractured soils (for example, limestone), backfilling can be omitted.

5.12. Sprinkling of filters should be done evenly in layers no more than 30 times the thickness of the sprinkling. After each next rise of the pipe above its lower edge, a layer of backfill must remain at least 0.5 m high.

5.13. Immediately after installing the filter column and the sand and gravel packing, it is necessary to carefully pump the well with an airlift. The well can be put into operation after it has been continuously pumped by an airlift for 1 day.

5.14. The pump should be lowered into the well to such a depth that when the valve on the discharge pipeline is fully open, the suction port of the pump is under water. When the dynamic level drops below the suction port, the pump should be lowered to a greater depth or, if this is not possible, the pump performance should be adjusted with a valve.

5.15. Installation of pumps in wells should be carried out after checking the wells for patency with a template with a diameter greater than the diameter of the pump.

5.16. Before lowering the submersible pump into the well, it is necessary to measure the insulation resistance of the motor windings, which must be at least 0.5 MΩ. The pump can be turned on no earlier than 1.5 hours after the descent. In this case, the resistance of the motor windings must be at least 0.5 MΩ.

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5.17. All dewatering wells must be equipped with valves, which will allow you to control the flow rate of the system during the pumping process. After the well is constructed, it is necessary to carry out a test pumping out of it.

5.18. Considering that the dewatering system must operate continuously, it is necessary to ensure the redundancy of its power supply by supplying power from two substations with supply from different sources or receiving electricity from one substation, but with two independent inputs from the high side, two independent transformers and two power cables from the bottom sides.

5.19. The power supply system of pumping units must have automatic protection against short circuit currents, overload, sudden power outages, and motor overheating. Water-lowering systems should be equipped with devices for automatically shutting down any unit when the water level in the water intake drops below the permissible level.

5.20. The filter part of vacuum wells and wellpoints of vacuum installations should be located at least 3 m below the ground level in order to exclude air leakage.

5.21. Measures should be taken to prevent damage or clogging of dewatering and observation wells by foreign objects. The heads of the latter must be equipped with lids with a locking device.

5.22. After the installation of a dewatering well, it must be checked for water absorption.

5.23. Before the general start-up of the system, it is necessary to start-up each well separately. The start-up of the entire dewatering system is formalized by an act.

5.24. The dewatering system should additionally include reserve wells (at least one), as well as reserve pumping units for open drainage (at least one), the number of which, depending on the service life, should be:

up to 1 year - 10%; up to 2 years - 15%; up to 3 years - 20%; more than 3 years - 25% of the total estimated number of installations.

5.25. During the operation of wellpoint systems, air infiltration into the suction system of the unit should be excluded.

In the process of hydraulic immersion of wellpoints, it is necessary to control the presence of a constant outflow from the wells, and also to exclude the installation of the wellpoint filter element in a low-permeable layer (s) of soil. In the absence of a spout or a sharp change in the flow rate of water coming from the well, it is necessary to check the throughput of the filter in bulk and, if necessary, remove the wellpoint and check whether the filter outlet is free and whether it has been clogged. It is also possible that the filter is installed in a highly permeable layer of soil, which absorbs the entire flow rate of water entering the wellpoint. In this case, when immersing the wellpoint, it is necessary to organize a joint supply of water and air.

Groundwater captured by wellpoints should not contain soil particles, sanding should be excluded.

5.26. Extraction of wellpoints from the ground during their dismantling is carried out by a special truck crane with a thrust stand, a drilling rig or using jacks.

5.27. With a wind force of 6 points or more, as well as with hail, heavy rain and at night on an unlit site, work on the installation of wellpoints is prohibited.

5.28. During the installation and operation of the wellpoint system, incoming and operational control should be carried out.

5.29. After the dewatering system is put into operation, pumping should be carried out continuously.

5.30. The rate of development of dewatering should correspond to the rate of earthworks provided for in the PPR when opening pits or trenches. A significant advance in level reduction in relation to the excavation schedule creates an unjustified reserve capacity of the water reduction system.

5.31. During the performance of dewatering works, the reduced WLL should be ahead of the level of development of the pit by the height of one tier, developed by earthmoving equipment, i.e. by 2.5 - 3 m. This condition will ensure the efficiency of earthworks "dry".

5.32. Monitoring the efficiency of the water reduction system should be carried out

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by regular measurements of WLL in observation wells. It is mandatory to install water meters that control the flow rate of the system. The results of measurements should be recorded in a special journal.

The initial measurement of WLL in observation wells should be carried out before the commissioning of the dewatering system.

5.33. Pumping units installed in reserve wells, as well as standby pumps of open installations, must be periodically put into operation in order to maintain them in working condition.

5.34. Measurements of the reduced WLL during the drawdown process should be carried out in all aquifers affected by the work of the drawdown system. Periodically, it is necessary to determine the chemical composition of pumped waters and their temperature at complex objects.

Observations of the PWL should be carried out 1 time in 10 days.

5.35. All data on the operation of water reduction plants should be displayed in the log:

results of WLL measurements in observation wells, flow rates of the system, time of stops and starts during the shift, replacement of pumps, condition of slopes, appearance of griffins.

5.36. Upon termination of the operation of a system consisting of dewatering wells, acts should be drawn up for the completion of well liquidation.

5.37. When operating dewatering systems in winter, pumping equipment and communications should be insulated, and it should also be possible to empty them during breaks in operation.

5.38. All permanent water-reducing and drainage devices used during the construction period, when put into permanent operation, must comply with the requirements of the project.

5.39. Dismantling of water-reducing installations should be started from the lower tier after completion of backfilling of pits and trenches or immediately before their flooding.

5.40. In the zone of influence of the dewatering, regular observations should be made of precipitation and the intensity of its growth for buildings and communications located there.

5.41. When carrying out dewatering works, measures should be taken to prevent decompaction of soils, as well as violation of the stability of the slopes of the pit and the foundations of adjacent structures.

5.42. Water flowing into the pit from the overlying layers, not captured by the dewatering system, must be diverted by drainage ditches to sumps and removed from them by open drainage pumps.

5.43. Monitoring the state of the bottom and slopes of an open pit during dewatering should be carried out daily. In the event of slipping slopes, suffusion, the appearance of griffins at the bottom of the pit, protective measures should be taken immediately: loosening the crushed stone layer on the slopes at the points of groundwater outlet, loading with a layer of crushed stone, putting unloading wells into operation, etc.

5.44. When the slope of the pit crosses impervious soils lying under the aquifer, a berm with a ditch for water drainage should be made on the roof of the aquiclude (if the project does not provide for drainage at this level).

5.45. When draining groundwater and surface water, flooding of structures, the formation of landslides, soil erosion, and swamping of the area should be excluded.

5.46. Before the start of earthworks, it is necessary to ensure the drainage of surface and groundwater using temporary or permanent devices, without violating the safety of existing structures.

5.47. When diverting surface and groundwater, it is necessary:

a) on the upper side of the recesses to intercept the flow of surface waters, use cavaliers and reserves arranged by a continuous contour, as well as permanent catchment and drainage structures or temporary ditches and embankments; ditches, if necessary, may have protective fastenings against erosion or filtration leaks;

b) cavaliers from the downstream side of the recesses should be poured with a break, mainly in low places, but at least every 50 m; the width of the gaps along the bottom must be at least 3 m;

c) lay the soil from upland and drainage ditches arranged on slopes in the form of a prism along the ditches from their downstream side;

d) when the location of upland and drainage ditches in the immediate vicinity of the linear

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recesses between the recess and the ditch, perform a banquet with a slope of its surface of 0.02 - 0.04 towards the upland ditch.

5.48. When pumping water from a pit developed by an underwater method, the rate of lowering the water level in it, in order to avoid disturbing the stability of the bottom and slopes, must correspond to the rate of lowering the level of groundwater outside it.

5.49. When arranging drainages, earthworks should be started from discharge areas moving towards higher elevations, and the laying of pipes and filter materials should be started from watershed areas moving towards the discharge or a pumping unit (permanent or temporary) to prevent the passage of unclarified water through the drainage.

5.50. When constructing reservoir drainages, violations in the mating of the crushed stone layer of the bed with the crushed stone sprinkling of pipes are unacceptable.

5.51. Laying of drainage pipes, installation of manholes and installation of equipment for drainage pumping stations must be carried out in compliance with the requirements of SP 81.13330 and SP 75.13330.

5.52. The list of as-built documentation for construction dewatering using wells should include:

a) the act of commissioning the water reduction system;

b) executive layout of wells;

c) executive schemes of well designs indicating the actual geological columns;

d) an act on the liquidation of wells upon completion of work;

e) certificates for the materials and products used.

5.53. When performing work on dewatering, organization of surface runoff and drainage, the composition of controlled indicators, limit deviations, scope and methods of control must comply with Table I.1 of Appendix I.

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6.1.1. The dimensions of the excavations adopted in the project must ensure the placement of structures and the mechanized performance of work on driving piles, installation of foundations, insulation, dewatering and drainage, and other work performed in the excavation, as well as the possibility of moving people in the bosom in accordance with 6.1.2. The dimensions of the recesses along the bottom in kind must be at least those established by the project.

6.1.2. If it is necessary to move people in the sinus, the distance between the surface of the slope and the side surface of the structure being erected in the excavation (except for the artificial foundations of pipelines, collectors, etc.) must be at least 0.6 m in the light.

6.1.3. The minimum width of trenches should be taken in the design of the largest of the values ​​that meet the following requirements:

for strip foundations and other underground structures - should include the width of the structure, taking into account the formwork, the thickness of the insulation and fasteners, with an addition of 0.2 m on each side;

for pipelines, except for main ones, with slopes of 1:0.5 and steeper - according to table 6.1;

for pipelines, except for main ones, with slopes of 1:0.5 - not less than the outer diameter of the pipe with the addition of 0.5 m when laying in separate pipes and 0.3 m when laying with lashes;

for pipelines in sections of curved inserts - at least twice the width of the trench in straight sections;

when arranging artificial bases for pipelines, except for soil bedding, collectors and underground channels - not less than the width of the base with an addition of 0.2 m on each side;

developed by single-bucket excavators - not less than the width of the cutting edge of the bucket with the addition of 0.15 m in sand and sandy loam, 0.1 m in clay soils, 0.4 m in loosened rocky and frozen soils.

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6.1.5. In pits, trenches and profile excavations, the development of eluvial soils that change their properties under the influence of atmospheric influences should be carried out, leaving a protective layer, the value of which and the permissible duration of contact of the exposed base with the atmosphere are established by the project, but not less than 0.2 m. The protective layer is removed immediately prior to the commencement of construction.

6.1.6. Excavations in soils, except for boulders, rocks and those specified in 6.1.5, should be developed, as a rule, up to the design mark, while maintaining the natural composition of the base soils. It is allowed to develop recesses in two stages: draft - with deviations given in pos. 1 - 4 of Table 6.3 and the final one (immediately before the erection of the structure) - with the deviations given in pos. 5 of the same table.

–  –  –

ConsultantPlus: note.

In the official text of the document, apparently, a typo was made: table 7.2 is missing.

6.1.8. Replenishment of bulkheads in places where foundations are laid and pipelines laid must be carried out with local soil with compaction to the density of the soil of the natural composition of the base or low-compressibility soil (deformation modulus of at least 20 MPa), taking into account Table 7.2. In subsiding soils of type II, the use of draining soil is not allowed.

6.1.9. The method of restoring foundations damaged as a result of freezing, flooding, as well as busting, must be agreed with the design organization.

6.1.10. The steepest slope of trenches, pits and other temporary excavations, arranged without fixing in soils above the groundwater level (taking into account capillary water rise according to 6.1.11), including in soils drained by artificial dewatering, should be taken in accordance with with the requirements of SNiP 12-04.

With a slope height of more than 5 m in homogeneous soils, their steepness is allowed to be taken according to the schedules of Appendix B, but not steeper than those indicated in SNiP 12-04 for an excavation depth of 5 m and in all soils (including rock) no more than 80 °. The steepness of the slopes of excavations developed in rocky soils using blasting must be established in the project.

6.1.11. If there is groundwater during the period of work within the excavations or near their bottom, not only soils located below the groundwater level, but also soils located above this level by the amount of capillary rise, which should be taken, should be considered wet:

0.3 m - for large, medium size and fine sands;

0.5 m - for silty sands and sandy loams;

1.0 m - for loams and clays.

6.1.12. The steepness of the slopes of underwater and flooded coastal trenches, as well as trenches developed in swamps, should be taken in accordance with the requirements of SP 86.13330.

6.1.13. The design should establish the steepness of the slopes of soil pits, reserves and permanent dumps after the completion of earthworks, depending on the directions of reclamation and methods of fixing the surface of the slopes.

6.1.14. The maximum depth of recesses with vertical loose walls should be taken in accordance with the requirements of SNiP 12-04.

6.1.15. The greatest height of the vertical walls of excavations in frozen soils, except for loosely frozen soils, at an average daily air temperature below minus 2 ° C, can be increased compared to the established SNiP 12-04 by the depth of soil freezing, but not more than 2 m.

6.1.16. The project should establish the need for temporary fastening of the vertical walls of trenches and pits, depending on the depth of the excavation, the type and condition of the soil, hydrogeological conditions, the magnitude and nature of temporary loads on the edge and other local conditions.

6.1.17. The number and size of ledges and local recesses within the excavation should be minimal and ensure mechanized cleaning of the base and manufacturability of the construction of the structure. The ratio of the height of the ledge to its base is established by the project, but must be at least 1:2 - in clay soils, 1:3 - in sandy soils.

6.1.18. If it is necessary to develop excavations in the immediate vicinity and below the soles of the foundations of existing buildings and structures, the project should provide for technical solutions to ensure their safety.

6.1.19. Places where developed cuts or embankments overlap on the security zones of existing underground and air communications, as well as underground structures, must be designated in the project, indicating the size of the security zone, established in accordance with the instructions of 6.1.21.

In case of detection of communications, underground structures or signs designating them that are not specified in the project, earthworks should be suspended, representatives of the customer, designer and organizations operating the discovered communications should be called to the work site, and measures should be taken to protect the discovered underground devices from damage.

6.1.20. Development of pits, trenches, excavations, embankment and opening of underground

–  –  –

communications within the protected zones are allowed with the written permission of the operating organizations and the conclusion of a specialized organization for assessing the impact of construction work on the technical condition of communications.

6.1.21. When crossing developed trenches and pits with existing communications that are not protected from mechanical damage, excavation by earthmoving machines is allowed at the following minimum distances:

for underground and overhead communication lines; polyethylene, steel welded, reinforced concrete, ceramic, cast iron and chrysotile cement pipelines, channels and collectors, with a diameter of up to 1 m from the side surface and 0.5 m above the top of communications with their preliminary detection with an accuracy of 0.25 m;

for power cables, main pipelines and other underground communications, as well as for boulder and blocky soils, regardless of the type of communications - 2 m from the side surface and 1 m above the top of the communications with their preliminary detection with an accuracy of 0.5 m.

The minimum distances to communications for which there are security rules should be assigned taking into account the requirements of these rules.

The remaining soil should be developed using manual non-impact tools or special mechanization tools.

6.1.22. The width of the opening of lanes of roads and city driveways during the development of trenches should be taken: for concrete or asphalt pavement on a concrete base - 10 cm more than the width of the trench along the top on each side, taking into account fasteners; with other pavement designs - by 25 cm.

For pavements made of prefabricated reinforced concrete slabs, the width of the opening should be a multiple of the size of the slab.

6.1.23. When developing soils containing oversized inclusions, the project must provide for measures for their destruction or removal from the site. Boulders, stones, pieces of loosened frozen and rocky soil are considered oversized, the largest size of which exceeds:

2/3 bucket width - for excavators equipped with a backhoe or direct digging equipment;

1/2 bucket width - for excavators equipped with a dragline;

2/3 of the largest design digging depth - for scrapers;

1/2 blade height - for bulldozers and graders;

1/2 of the body width and by weight half of the nameplate capacity - for vehicles;

3/4 of the smaller side of the intake opening - for the crusher;

30 cm - when developing manually with removal by cranes.

6.1.24. In case of artificial salinization of soils, the salt concentration in the pore moisture of more than 10% is not allowed in the presence or intended laying of uninsulated metal or reinforced concrete structures at a distance of less than 10 m from the place of salinization.

6.1.25. When soil thaws near underground utilities, the heating temperature should not exceed a value that causes damage to their shell or insulation. The maximum allowable temperature must be specified by the operating organization when issuing a permit for excavation.

6.1.26. The width of the roadway of the access roads within the developed excavations and soil quarries should be for dump trucks with a carrying capacity of up to 12 tons for two-way traffic - 7 m, for one-way traffic - 3.5 m.

With a load capacity of dump trucks of more than 12 tons, as well as when using other vehicles, the width of the carriageway is determined by the construction organization project.

6.1.27. Terms and methods of excavation in permafrost soils used according to principle I should ensure the preservation of permafrost in the foundations of structures.

Appropriate protective measures should be provided for by the project.

6.1.28. When performing work on the development of excavations and the arrangement of natural foundations, the composition of controlled indicators, permissible deviations, the scope and methods of control must comply with Table 6.3.

–  –  –

6.2.1.1. The rules of this section apply to the production and acceptance of work performed by the method of hydraulic mechanization during the reclamation of structures, as well as in mining and overburden work in construction quarries.

6.2.1.2. Geotechnical surveys of soils subject to hydromechanized development must meet the specific requirements of SP 47.13330.

6.2.1.3. If the content in the soil is more than 0.5% of the volume of inclusions oversized for soil pumps (boulders, stones, driftwood), it is prohibited to use suction dredgers and installations with soil pumps without devices for the preliminary selection of such inclusions. Oversized should be considered inclusions with an average transverse size of more than 0.8 of the minimum flow area of ​​the pump.

6.2.1.4. When laying pressure slurry pipelines, the turning radii must be at least 3-6 pipe diameters. At turns with an angle of more than 30°, slurry pipelines and water conduits must be fixed.

All pressure slurry pipelines must be tested to the maximum working pressure.

The correct laying and reliability in the operation of pipelines are documented by an act drawn up based on the results of their operation within 24 hours of working time.

6.2.1.5. The parameters for the development of cuts and quarries with floating suction dredgers and maximum deviations from the marks and dimensions established in the PPR should be taken from Table 6.5.

–  –  –

6.2.1.6. When developing excavations by means of hydraulic mechanization, the composition of controlled indicators, the volume and methods of control must comply with the instructions in Table 6.6.

–  –  –

6.2.2.1. The technology of alluvium of earthworks, soil piles must comply with special instructions in the POS and PPR. Alluvium of pressure hydraulic structures without technical conditions for their construction is not allowed.

6.2.2.2. The steepness of the forcedly formed slopes of alluvial structures should be assigned taking into account water loss and seepage during the construction period. For coarse sands, the slope should not be steeper than 1:2, medium size - 1:2.5, for fine sands - 1:3 and especially fine dusty - 1:4.

6.2.2.3. Alluvium with free spreading of the pulp (free slope) should be used in the construction of earthworks with a spread or wave-resistant profile; the steepness of the free slope should be taken according to SP 39.13330.

6.2.2.4. The excess of soil above the water surface during the reclamation of the underwater parts of structures and in swampy or flooded areas in the alignment of the embankment device and along the axis of laying the slurry pipelines from which the reclamation is carried out should be at least, m:

for gravel soils 0.5;

for sand and gravel 0.7;

for sands of large and medium size 1.0;

–  –  –

for finer sands 1.5.

The specified values ​​can be increased according to the conditions of safe work. When arranging embankments on peat, peaty soils and silts, and when alluvium into flowing water, the excess should not be less than that established in the design of the structure and the POS.

6.2.2.5. The embankment during the construction of the structure (passing embankment) should be carried out from reclaimed or imported soil, if the latter is provided for by the PIC. The use of silty or frozen soil for embankment dams, as well as soil containing more than 5% soluble salts, is not allowed. Dams from imported soil should be backfilled in layers with compaction to the values ​​accepted for alluvial soil.

6.2.2.6. Drainage devices laid inside earthen alluvial structures should be protected before washing with a layer of dry sandy soil 1-2 m thick, or by other methods provided for in the POS. The backfill soil should have the same granulometric composition as the one being washed or be more coarse-grained.

6.2.2.7. After the end of the alluvium, the upper part of the spillway wells and racks of the overpasses should be dug out and cut off at a depth of at least 0.5 m from the design mark of the crest of the structure to be washed.

6.2.2.8. The volume of developed soil for alluvium of structures (intermediate piles) should be set taking into account the margin for replenishing losses according to tables 6.7 and 6.8. The volume of losses should be calculated in relation to the profile volume of the embankment being erected.

–  –  –

6.2.2.9. During the production of alluvial works, the composition of controlled indicators, limit deviations, the scope and methods of control must comply with Table 6.9.

–  –  –

6.2.2.10. Instructions on the specifics of the production of hydromechanized works on the arrangement of earthworks, stacks and dumps are given in Appendix K.

–  –  –

6.2.3.1. Engineering preparation of the territory by hydraulic filling is carried out:

1) when the floodplain territory is composed of weak soils (peat, silt, peaty and clayey water-saturated soils);

2) if necessary, raising the level of river floodplains and the surface;

3) when planning a terrain cut by ravines.

6.2.3.2. The technological process of land reclamation for industrial and civil construction consists of a set of measures that ensure the design hydraulic and technological parameters of reclamation. The main task of the alluvium technology used is to ensure the design density of soil laying in an artificial base, expressed by the volumetric weight of the soil skeleton or the compaction coefficient. The whole complex of measures and the sequence of their implementation are determined by the project for the production of works, which is compiled by the organization on the basis of the approved design and estimate documentation.

6.2.3.3. The project for the production of works on reclamation of territories should include the following materials:

topographic and geological characteristics of quarries intended for use for alluvial land;

quarry plan with a breakdown into separate sections, homogeneous in terms of the weighted average granulometric composition of the soil, indicating the order of development and volumes of all allocated quarry sections;

plan of the alluvial area, which indicates the breakdown into separate alluvium maps, the order of alluvium linked to the order of development of the quarry sites, the location of spillway wells and by draining clarified water, the planned and high-altitude location of the main slurry pipelines during the alluvium of each map;

schemes for the production of works for each of the maps indicating the sequence of alluvium, the average particle size distribution allowed for laying on the soil map, the permissible deviations from this average grain composition, the planned and high-altitude location of alluvial communications on the map, the permissible intensity of alluvium of the map per day, consistency requirements pulps;

design and dimensions of embankment and fencing of alluvium maps, pipelines, spillways;

a list of measures to prepare the surface of the natural area for alluvium;

schedule and estimated cost of all types of work.

6.2.3.4. When reclamation, the following requirements must be met:

to ensure a uniform distribution of the washed soil over the area of ​​the map to create a layer of washed soils that is homogeneous in terms of granulometric composition. The degree of homogeneity is established by the project;

within the limits of the entire map to be washed, lay only such soils, the granulometric composition of which is within the limits allowed by the project. Poor-quality soil washed in the territory can be left only if agreed with the design organization, otherwise it must be removed.

6.2.3.5. Quarry soils used for alluvium of the territory must meet the following requirements: suitability for granulometric composition, small distances from the quarry to alluvium maps, allowable estimated depth of the face. When evaluating quarry soils, the difficulty of development depending on the category of soil and the required qualities of the reclaimed soil should also be taken into account.

6.2.3.6. The assessment of the suitability of quarry soils intended for use for reclamation of the territory is made on the basis of the basic requirement that the reclamation area must be formed by soils of a certain granulometric composition approved for laying.

–  –  –

The established average soil composition allowed for laying on the area to be washed and the limits of permissible deviation from this average composition are recommended to be presented in the form of particle size distribution curves.

If the curve of the average particle size distribution of the quarry soils (or its sections) is below the average particle size distribution curve allowed for laying on the territory, it is necessary to consider and choose the most economical of the following options:

the possibility of further reducing the percentage of washed fine fractions;

alluvium of the territory with soils with higher characteristics of building properties, without reducing the percentage of washed fine fractions.

If the particle size distribution curve of the quarry soils is located above the particle size distribution curve allowed for laying, it is necessary to calculate the amount of soil fractions to be washed out.

The determination of the total amount of fine fractions to be washed out should be made taking into account the provision of the necessary physical and mechanical properties of the reclaimed soil stratum and technical and economic calculations that establish the feasibility of choosing this open pit with the percentage of washing out of fine fractions.

6.2.3.7. The sequence and method of working the face with a dredger are determined in accordance with the physical and mechanical properties of quarry soils and are fixed by the technological map for the development of soil in a quarry. The technological map is an integral part of the project for the production of works and includes:

soil characteristics in the form of averaged granulometric composition;

differentiation of the entire volume of soil to be developed into groups according to the difficulty of development and transportation;

geological and lithological sections for separate blocks into which the entire area of ​​the quarry is divided;

a method for developing a quarry, taking into account the design capacity of the face and the compression characteristics of the quarry soils in natural occurrence;

quarry development scheme with a breakdown of each block into separate slots.

6.2.3.8. Overburden soils of a quarry, when substantiated in the POS, are allowed to be left in the main face and developed together with useful soil, provided that the technology for alluvial disposal of the discharge area of ​​the required amount of fine fractions is provided.

6.2.3.9. The excavation of soil from the quarry must be carried out in accordance with the specifications for its reclamation, while the stability of non-working slopes of the quarry, the laying of which is determined by the mining and technical part of the main project for the development and reclamation of the quarry, must be ensured.

6.2.3.10. With a heterogeneous composition of soils in a quarry, it is advisable to selectively develop a face with laying lower quality soils on separate sections of the projected area with a small bearing capacity (green zone, areas with low-rise buildings, underground roads, etc.).

6.2.3.11. The method and technological scheme of alluvial land reclamation (pulp distribution on the alluvium map) are recommended by the construction organization project, taking into account the mineralogical and granulometric composition of the quarry soil, the hydraulic characteristics of the pulp flow, which determine the layout of the soil along the alluvial slope and the texture of the alluvial soil, and technological parameters (pulp consistency during alluvium , its specific consumption and intensity of alluvium).

Technological schemes should also take into account the features of the terrain, the type and capacity of the existing dredgers and the equipment of the distributing network of slurry pipelines, the required order of development of the area to be washed, the size and height of the soil layer to be washed.

When choosing a technological scheme, it should be taken into account that the required packing density of the washed sandy soil is determined by the specific consumption, the consistency of the solid and liquid components, and the intensity of the alluvium.

6.2.3.12. The soil laying methods recommended by the project should be reflected in the optimal technological scheme that provides the highest density of the reclaimed base with minimal heterogeneity of the reclaimed soils. When alluvial sandy soils are laid, the density of their laying, characterized by the volumetric weight of the skeleton, should be in the range of 15.5 - 16.0 kN / m3 or more.

The volumetric mass of the skeleton of the reclaimed soil is controlled under production conditions by geotechnical

–  –  –

fasting according to the results of analyzes of samples of samples taken every 0.5 m of alluvium.

6.2.3.13. Alluvium of the territory with sandy soils is recommended to be carried out by a non-trestle method with a concentrated release of pulp from the end of the distribution slurry pipeline, which consists of separate sections with quick-coupling socket connections. Depending on the average diameter of sand particles, the thickness of the layer being washed varies from 0.5 to 1.0 m. In the process of washing, the distributing slurry pipeline moves parallel to the crest of the outer slope of the embankment and is at a distance of 7 - 8 m from the bottom of the inner slope of the primary and secondary embankment.

6.2.3.14. When reclamation of floodplain territories, a mosaic scheme is also recommended, which is characterized by a dispersed pulp discharge from a group of outlets located along a certain grid on a significant part of the reclamation map, which causes mutual damping of the velocities of oncoming pulp flows and ensures a uniform distribution of the bulk of the soil over the area being simultaneously washed. Pulp discharge points should be located at approximately equal distance from each other, forming a certain grid on the alluvium map.

6.2.3.15. The flow diagram of alluvium should provide for the development of a main slurry pipeline, the arrangement of pulp outlets and a spillway system that allows periodically changing the direction of clarified water flow on the slurry map.

6.2.3.16. The outer slopes of the area to be washed in are formed by means of dams of primary and associated embankment, which are backfilled, respectively, before and during the process of reclamation of the territory. The position of these dams should ensure the formation of a general slope of the area to be washed.

6.2.3.17. Under-washing up to the design level, which ensures flood-free and flood-free territory, is not allowed. The average washout height, defined as the arithmetic mean over the entire surface of the reclaimed area, should not exceed 0.1 m. Deviations from the design mark in some areas are allowed no more than minus 0.2 and plus 0.3 m.

6.2.3.18. The alluvium schemes established by the project, the granulometric composition of the soil allowed for laying, the percentage of washing out of small fractions of the soil can be changed based on the data obtained during the production of an experimental alluvium or during the alluvium of the territory, subject to the agreement of the changes with the design organization.

6.2.3.19. All works on the alluvium of territories for industrial and civil construction should be carried out with specially organized supervision of their quality. The work performed during the reclamation of territories must be carried out in compliance with the safety requirements provided for by special instructions.

7. Fills and backfills

7.1. In the projects of embankments (working and production works), including: embankments of access roads, roads and railways, dams, planning embankments, on-farm networks, etc., as well as backfilling of pits, trenches, the following must be indicated:

dimensions in plan and height of embankments and backfills in general and their individual sections with different: dimensions in height (in 2 - 4 m); loads on the surface of compacted soil;

types of dumped soils;

the required degree of compaction of soils for homogeneous in appearance and composition of soils - the density in the dry state, and heterogeneous - the compaction coefficient;

thickness of soil layers to be poured for each type of soil-compacting equipment and a given degree of soil compaction;

requirements for the preparation of the surface (base) of the embankment and backfill;

requirements for geotechnical monitoring.

7.2. For embankments and backfilling, as a rule, local coarse, sandy, clayey soils, as well as environmentally friendly industrial waste should be used.

–  –  –

industries similar in type and composition to soils of natural origin that meet the requirements of Appendix M.

In agreement with the customer and the design organization, the soils accepted in the project for embankments and backfilling can be replaced if necessary.

7.3. When using soils of different types in the same embankment, the following requirements must be met:

it is not allowed to pour soils of different types in one layer, if this is not provided for by the project;

the surface of layers of less draining soils, located under layers of more draining ones, should have a slope within 0.04 - 0.1 from the axis of the embankment to the edges.

7.4. For backfilling at a distance of less than 10 m from existing or planned non-insulated metal or reinforced concrete structures, the use of soils with a concentration of soluble salts in groundwater over 10% is not allowed.

7.5. When used for embankments and backfilling of soils containing solid inclusions within the limits allowed by Appendix M, the latter should be evenly distributed in the poured soil and located no closer than 0.2 m from isolated structures, and frozen clods, in addition, no closer than 1.0 m from the slope of the embankment.

7.6. When laying the soil "dry", with the exception of road embankments, compaction should be carried out, as a rule, at a moisture content w, which should be in the range where

Optimum humidity determined in a standard compaction device according to GOST 22733.

Coefficients A and B should be taken according to Table 7.1 with subsequent refinement based on the results of the pilot compaction according to Appendix D.

–  –  –

When using coarse-grained soils with clay filler, the moisture content at the border of rolling and fluidity is determined by fine-grained (less than 2 mm) filler and is recalculated for the soil mixture.

7.7. If there is a shortage of quarries with soils that meet the requirements of 7.6 in the construction area, and if, due to the climatic conditions of the construction area, natural drying of the soil is impossible, and drying the soil in special installations or by special methods is not economically feasible, in some cases it is allowed to use soil of increased moisture with making appropriate changes to the project.

7.8. Surface preparation for embankment typically includes:

removal and uprooting of trees, shrubs, stumps and their roots;

removal of grass and swamp vegetation;

cutting of the soil-vegetative layer, peaty, silty and other soil with organic matter content in

–  –  –

removal of the upper loosened (liquefied), frozen layer of soil, snow, ice, etc.;

backfilling on the prepared surface of a carrier layer 0.2 - 0.4 m thick of coarse gravel sand, crushed stone soil with its compaction by bulldozers, on which vehicles and other construction machines and mechanisms can freely move and maneuver.

Surface preparation when backfilling pits and trenches is carried out by removing wood and other decaying construction waste and household waste from the bottom.

7.9. Experimental compaction of embankment soils and backfills should be carried out if there are instructions in the project, and in the absence of special instructions - with a volume of surface compaction at the facility of 10 thousand m3 or more.

As a result of experimental compaction, the following should be installed:

a) in laboratory conditions according to GOST 22733:

maximum density values ​​of compacted soils;

optimal humidity at which maximum densities are achieved;

admissible ranges of changes in the moisture content of the compacted soil and, accordingly, the values ​​of indicators A and B according to Table 7.1, at which the specified compaction coefficients are achieved for all types of soils used;

density values ​​of compacted soils, at given values, or vice versa, values ​​of compaction coefficients of compacted soils at given values;

b) the thickness of the layers to be poured, the number of passes of compacting machines along one track, the duration of the impact of vibration and other working bodies on the soil, the number of impacts and the height of the rammers during compaction to "failure", ramming of pits and other technological parameters that ensure the design density of the soil;

c) the values ​​of indirect indicators of compaction quality subject to operational control ("failure" for compaction by rolling, tamping, the number of impacts of a dynamic density meter, etc.).

If the experimental compaction is planned to be carried out within the embankment being erected, the places of work should be indicated in the project.

When compacting soils in embankments and backfills by rolling, tamping, vibration, as well as soil piles, hydraulic vibration compaction, weights with vertical drains, including when making soil cushions, experimental compaction should be carried out in accordance with Appendix D.

7.10. When erecting embankments, the width of which at the top does not allow for a turn or passing of vehicles, the embankment must be backfilled with local widenings for the construction of turning or passing platforms. Additional volumes of earthworks should be taken into account in the POS.

7.11. Soils poured into the embankment and used for backfilling must meet the requirements of Appendix M and have a moisture content close to optimal.

When the soil moisture is low, it is necessary to moisten them with the calculated amount of water, as a rule, in a quarry or reserve, or in the process of backfilling and leveling individual layers by uniformly spraying water from hoses with mixing the wetted soils with bulldozers.

Compaction of soils that have been moistened during backfilling should be carried out 0.5–2 days after a sufficiently complete distribution of water over the entire volume of the backfilled layer.

With increased soil moisture, partial drying of clay soils is possible:

in dry summer time on an intermediate reserve with periodic mixing of soils;

in the process of backfilling and leveling individual layers of waterlogged soil with a uniform addition of the calculated amount of dry quicklime to it according to a specially developed

–  –  –

methodology.

7.12. Backfilling of individual layers of soils into an embankment with a moisture content close to optimal should be carried out, as a rule, by an advancing front with the movement of vehicles along the newly backfilled layer with its simultaneous compaction. At the same time, the movement of vehicles should be organized in such a way that vehicles loaded with soil pass through the pre-compacted soil with a bulldozer, light pneumatic rollers, and unloaded dump trucks pass through the areas of the newly backfilled layer, performing preliminary compaction of loose soil.

7.13. It is recommended to backfill soils with low humidity into the embankment with a retreating front with the movement of dump trucks and other mechanisms along the layer previously filled, compacted and accepted for further work. At the same time, it is necessary to organize the movement of dump trucks and other construction vehicles in such a way as to exclude decompaction of the previously compacted soil layer due to the formation of ruts and other factors.

7.14. The thickness of the poured layers of clay soils in a loose state should be taken at 15

20%, and sandy ones by 10 - 15% more than those specified in the project, which should be clarified based on the results of the pilot compaction according to Appendix G.

In the event that the thickness of the backfilled and partially or fully compacted layer turns out to be greater than that specified in the project and refined according to the results of experimental compaction, it is necessary to cut off the upper excess part of it or to compact such a layer with heavier soil-compacting mechanisms, or with an increased number of their passes in 1, 5 - 2 times.

7.15. Compaction of soils in embankments and backfills should be carried out by separate cards (grippers) and at each of them by separate stages so that at each stage 3-6 ramming strokes or passes of the skating rink (loaded dump truck) are performed, or one pass of vibration, vibro-impact cars.

Compaction must be carried out with overlapping of the impact marks of the soil compactor, the compacting mechanism by 0.05 - 0.1 of the track width.

After compaction is completed, the compacted surface should be leveled by 1 - 2 passes of a smaller soil compactor (roller, bulldozer, etc.).

When choosing mechanisms and modes of soil compaction according to 7.2 - 7.15 in projects, it is recommended to be guided by Appendix G.

7.16. Backfilling of trenches with laid pipelines in ordinary non-sagging and other soils should be carried out in two stages.

At the first stage, the lower zone is backfilled with non-frozen soil that does not contain solid inclusions larger than 1/10 of the diameter of chrysotile-cement, plastic, ceramic and reinforced concrete pipes to a height of 0.5 m above the top of the pipe, and for other pipes - soil without inclusions larger than 1/10 4 of their diameters to a height of 0.2 m above the top of the pipe with padding of the sinuses and its uniform layer-by-layer compaction to the design density on both sides of the pipe. When backfilling, the pipe insulation must not be damaged. Joints of pressure pipelines are backfilled after preliminary testing of communications for strength and tightness in accordance with the requirements of SP 129.13330.

At the second stage, the upper zone of the trench is backfilled with soil that does not contain solid inclusions larger than the pipe diameter. At the same time, the safety of the pipeline and the density of the soil, established by the project, must be ensured.

7.17. Backfilling of trenches with impassable underground channels in ordinary non-subsidence and other soils should be carried out in two stages.

At the first stage, the lower zone of the trench is backfilled to a height of 0.2 m above the top of the channel with non-frozen soil that does not contain solid inclusions larger than 1/4 of the channel height, but not more than 20 cm, with its layer-by-layer compaction to the design density on both sides of the channel .

At the second stage, the upper zone of the trench is backfilled with soil that does not contain solid inclusions larger than 1/2 of the channel height. At the same time, the safety of the channel and the density of the soil, established by the project, must be ensured.

7.18. Embankments up to 4 m high and backfilling of trenches, to which no additional loads are transferred (except for the own weight of the soil), can be performed without soil compaction, but with an excess height depending on its thickness by 3 - 5% made of sand, and 6 - 10% - from clay soils or with backfilling along the route of the trench of the roller, the height of which should be taken according to

–  –  –

analogy with the above for the embankment. The presence of a roller should not interfere with the use of the territory in accordance with its purpose.

7.19. Backfilling of main pipelines, closed drainage and cables should be carried out in accordance with the rules of work established by the relevant codes of practice.

7.20. Trenches and pits, except for those developed in type II subsiding soils, at intersections with existing roads and other areas with road surfaces, should be covered to the full depth with sandy or pebble soil, screening of crushed stone or other similar low-compressibility (strain modulus of 20 MPa or more) local materials that do not have cementing properties, with a seal. If these materials are not available in the construction area, it is allowed, by a joint decision of the customer, the contractor and the design organization, to use sandy loam and loam for backfilling, provided that they are compacted to the design density.

Backfilling of trenches in areas where the project provides for the construction of subgrade railways and roads, the foundations of airfield and other pavements of a similar type, hydraulic embankments, must be carried out in accordance with the requirements of the relevant sets of rules.

7.21. At the intersection of trenches, except for those developed in subsiding soils, with existing underground utilities (pipelines, cables, etc.)

) passing within the depth of the trenches, backfilling under existing communications with non-frozen sand or other low-compressibility (deformation modulus 20 MPa or more) soil should be performed over the entire cross section of the trench to a height of up to half the diameter of the pipeline (cable) being crossed or its protective sheath with layered soil compaction. Along the trench, the size of the bedding along the top should be 0.5 m more on each side of the pipeline (cable) or its protective sheath being crossed, and the slopes of the bedding should not be steeper than 1:1.

If the project provides for devices that ensure the invariability of the position and the safety of the crossed communications, backfilling of the trench should be carried out in accordance with 7.16.

7.22. Backfilling of narrow sinuses, including those performed in subsiding soils of type II, is recommended to be dumped immediately to the full depth, followed by compaction of clay soils with soil piles, or by vertical reinforcement by punching holes with a pneumatic punch, followed by filling them with poured concrete of class B7.5 on fine aggregate.

7.23. In embankments with rigid slope support and in other cases, when the soil density on the slope must be equal to the density in the body of the embankment, the embankment should be backfilled with a technological widening, the value of which is set in the project depending on the steepness of the slope, the thickness of the layers being poured, the natural slope of the loosely poured soil and the minimum allowable approach of the compacting mechanism to the edge of the embankment. The soil cut from the slopes can be re-laid into the body of the embankment.

7.24. In order to organize passages along the dumped rock fill over the entire area, it is necessary to pour a leveling layer of fine rocky soil (piece size up to 50 mm) or coarse sand.

7.25. When performing work in rainy autumn time, it is necessary to protect the soil in reserves from waterlogging, and in dry summer time from excessive drying. Under these conditions, the soil poured into separate cards must be immediately compacted to the required density.

At the same time, the dimensions of the maps in the plan are taken in such a way that the backfilling and compaction of soil layers are carried out during one shift.

7.26. Work on the implementation of embankments and backfilling at low temperatures should be carried out taking into account the following requirements:

preparation of the surface (base) of the embankment and backfills should be carried out with the complete removal of snow, ice, a frozen layer of weak and heaving soil to its entire depth;

filling into the embankment and backfilling of soils must be carried out at their natural moisture content and in a thawed state with the content of frozen soil clods not exceeding the requirements given in Appendix M and, as a rule, on previously unfrozen, filled and compacted layers.

at low humidity of the dumped soils, more

–  –  –

heavy soil compaction equipment;

work on backfilling and compaction of each layer must be carried out during one work shift;

when making embankments from clay soils with heavy snowfall, all work should stop;

breaks in work on the implementation of embankments and backfilling are allowed only under the conditions that during the break the freezing depth of previously compacted heaving soils does not exceed 15 cm or during the break the previously compacted soils are insulated with special means (for example, low-moisture loose soil, which is subsequently removed) ;

all work on filling soils and their compaction is carried out with increased intensity.

7.27. In the process of performing work on the installation of embankments and backfilling, the following is carried out:

a) input control over the type and main physical indicators of soils supplied for filling and backfilling; types and main characteristics of soil-compacting machines, performed mainly by the registration method;

b) operational control, measuring and visual, of the types and moisture content of the soil poured into each layer; the thickness of the poured layers; if necessary, additional moistening of soils with the uniformity and amount of water poured; uniformity and number of passes (blows) of soil-compacting machines over the entire area of ​​the layer and, especially, on slopes near existing structures; performance of work on sealing quality control;

c) acceptance control for each layer and in general for the object or its parts is carried out by measuring methods, as well as according to design documentation in accordance with the requirements of Appendix M.

7.28. When using soils of high humidity in the PPR, zones of embankments should be provided, filled by alternating a layer of draining (sand, gravel, etc.) soil, which ensures drainage of waterlogged clay soil laid on top under the action of its own weight, and the possibility of moving vehicles and mechanisms along dump cards.

7.29. Losses of soil during transportation to earthworks by vehicles, scrapers and earth carriers should be taken into account when transporting at a distance of up to 1 km - 0.5%, at long distances - 1.0%.

7.30. Losses of soil when moving it with bulldozers on a base composed of soil of a different type should be taken into account when backfilling trenches and pits - 1.5%, when laying in an embankment - 2.5%.

It is allowed to accept a larger percentage of losses with sufficient justification, by a joint decision of the customer and the contractor.

7.31. When performing work on the construction of embankments and backfills, the composition of controlled indicators, limit deviations, the volume and methods of control must comply with Appendix M. The points for determining indicators of soil characteristics must be evenly distributed over the area and depth.

8. Earthworks in special soil conditions

8.1. Earthworks in special soil conditions include: vertical planning of the construction site; engineering preparation of the construction site; excerpt of a foundation pit for a structure; compaction of base soils, carried out in accordance with the requirements of section 16.2 and Appendix D; backfilling of pits and trenches. The need for high-quality implementation of each of these stages of excavation is caused by the fact that they, individually and as a whole, are one of the measures that ensure the normal operation of buildings and structures under construction.

8.2. The vertical planning of the construction site and the territory as a whole should be carried out, if possible, with the preservation of natural runoff of surface rain and melt water, by cutting and backfilling soils with the device, in the latter case, of planning embankments.

On sites with hilly or large slopes of the relief, vertical planning is carried out with ledges or slight slopes.

In the areas of cutting and adding soil, as a rule, the soil-vegetative layer is completely cut off for the subsequent creation of a fertile layer within the green zones.

–  –  –

Planning embankments, which are the foundation of buildings and structures, utilities, roads, etc. on low-moisture subsidence, swelling, saline and other soils, they are carried out by dry method from local clayey, less often sandy soils according to the requirements given in Section 8, and on organomineral and organic, weak and other water-saturated soils, by hydraulic filling, as a rule, sandy soils.

8.3. The lower part of the planning embankment on subsiding soils with type II soil conditions, which is a low-permeable screen with a thickness, should be made of loam with their compaction to a compaction factor, and if necessary, an ecological screen under the foundations of structures made of clay with a plasticity number with compaction to a compaction factor and thick.

The use of drainage materials for the construction of planning embankments on sites with type II subsidence is not allowed.

8.4. On swollen and saline soils, leveling embankments under foundations and around structures, engineering communications in strips with a width of at least or (respectively, the thickness below the underlying layer of swelling or saline soil) must be made from non-swelling and non-saline soils.

Swelling and saline soils are allowed to be used only in areas of green areas located between structures and utilities.

8.5. When constructing leveling embankments, as well as backfilling in arid regions, it is allowed to use mineralized water to moisten the soil, provided that the total amount of soluble salts in the soil after compaction does not exceed the allowable limits established by the project.

8.6. Temporary roads for the operation of construction equipment should be laid according to the project, as a rule, along the routes of future main roads and internal driveways with a crushed stone-soil coating 0.2 - 0.4 m thick on a compacted base to a depth of 1 - 1.5 m to the value of the coefficient seals on subsidence, saline clay soils, as well as on areas of the planning embankment.

At the intersections of the main temporary roads, reinforced concrete road slabs should be laid on a crushed stone-soil pavement.

8.7. When performing work on saline soils during the dry period in arid regions, the POS should provide for duplication of temporary road routes.

The upper layer of saline soil with a thickness of at least 5 cm must be removed from the surface of the base of the planning embankment of temporary roads of reserves and quarries.

8.8. The development of pits in subsidence, swelling and saline soils should be carried out taking into account the requirements of Section 6 only after the implementation of measures according to 8.2 - 8.5.

The dimensions of the pits are taken according to the project and must exceed the dimensions of the compacted area of ​​the foundation soils for the foundations by at least 1.5 m in each direction, and in cases of using pile foundations - 1.0 m from the edges of the grillages.

Entrances and exits from the pits should be carried out from the downstream side.

To ensure the maneuvering of heavy machines during deep compaction of soils, the construction of pile foundations, it is advisable to pour crushed stone, pebble soil, crushed stone, etc. on the bottom of open pits in subsiding soils. layer 0.15 - 0.30 m thick.

In order to preserve the natural moisture content of soils from waterlogging or drying, and in winter the thawed state of soils, the excavation of pits should be carried out in separate maps (captures), the dimensions of which are assigned in the plan taking into account the intensity of the foundations.

8.9. In winter, the surface of the bottom of the pit, the compacted base should be protected from freezing, and before laying the foundations with a grillage, remove snow, ice, frozen loosened soil.

8.10. Backfilling of pits, trenches should be carried out immediately after the installation of foundations, underground parts of buildings and structures, laying of utilities in accordance with the requirements of Section 7, as a rule, clay, non-swelling and non-saline

–  –  –

Swelling soils can be used when backfilling trenches within green areas, as well as backfilling pits, provided that a non-swelling damping layer is poured along the foundation structures or underground parts of buildings and structures, which absorbs swelling deformations. The width of the damping layer is set by the project.

8.11. In the course of earthworks on soft soils, on temporary roads and on the surface of dumps, according to the instructions of the project, measures must be taken to ensure the operation and passage of construction equipment and vehicles (filling the drainage layer of soil, the use of geotextile materials, etc.).

8.12. The method of erecting planning, as well as road embankments and other earthworks on peaty, weak soils is determined by the project and is carried out with layer-by-layer backfilling and compaction with soil according to the requirements of Section 17 or by hydraulic filling of sandy soils.

8.13. In projects for hydraulic reclamation of soils, the following should be provided:

work on preparing the base for the alluvial leveling embankment in accordance with the requirements of Table 7.1;

backfilling at the base of the inundated embankment of a drainage layer of pebble (gravel), coarse sands, crushed stone to collect excess water and a system for collecting it and removing it from the site;

measures for a fairly uniform distribution of the pulp over the entire area of ​​the washed area;

requirements for the control of the physical and mechanical characteristics of alluvial soils, the main parameters of alluvial embankments, types and methods of control.

8.14. In cases of using soft soils (according to SP 34.13330) as the bases of roads and sites, the sod layer should not be removed.

8.15. When erecting embankments on soft soils, in agreement with the customer and the design organization, surface and depth marks should be installed in characteristic areas to monitor the deformations of the embankment and its underlying natural soils, as well as clarify the actual scope of work.

8.16. When performing earthworks in areas of shifting sands, the POS should provide for measures to protect embankments and excavations from drifts and blowing during the construction period (the procedure for developing reserves, advancing the installation of protective layers, etc.).

Blowout protective layers of clayey soil over sand should be laid in strips with an overlap of 0.5 - 1.5 m, and therefore the project must provide for an additional volume of soil in the amount of 10 - 15% of the total volume of the protective layer.

8.17. When embankments are erected in areas of shifting sands, soil losses due to blowing should be taken into account in the design, taking into account the effectiveness of the measures against blowing provided, according to analogues or special studies, but not more than 30%.

8.18. In the POS on landslide-prone slopes, the following should be established: the boundaries of the landslide-prone zone, the mode of soil development, the intensity of development or backfilling in time, linking the sequence of cuts (embankments) and their parts with engineering measures that ensure the overall stability of the slope, means and mode of position control and advance dangerous slope condition.

8.19. It is prohibited to carry out work on slopes and adjacent areas in the presence of cracks, stabs on them until the implementation of appropriate anti-landslide measures.

In the event of a potentially dangerous situation, all types of work should be stopped.

The resumption of work is allowed only after the complete elimination of the causes of the dangerous situation with the execution of the relevant permit.

9. Explosive work in soils

9.1. When performing blasting in construction, the following must be ensured:

in accordance with the uniform safety rules for blasting - the safety of people;

within the limits established by the project - the safety of existing structures, equipment, engineering and transport communications located in the zone of possible influence of blasting, as well as non-violation of production processes in industrial, agricultural and other

–  –  –

enterprises, measures for the protection of nature.

If damage to existing and under construction buildings and structures cannot be completely excluded during blasting, then possible damage should be indicated in the project.

Appropriate decisions should be agreed with the organizations concerned.

In the working documentation for blasting and the project for the production of blasting near critical engineering structures and existing industries, special technical requirements and conditions for agreeing on blasting projects presented by organizations operating these structures should be taken into account.

9.2. Working documentation for blasting operations in particularly difficult conditions should be developed as part of the project by the general design organization or, on its instructions, by a specialized subcontractor. At the same time, technical and organizational solutions for the safety of explosions should be provided in accordance with the requirements of special instructions of the relevant departments. Particularly difficult conditions should be considered blasting near railways, main pipelines, bridges, tunnels, power lines and communication lines, operating enterprises and operated residential buildings and structures, underwater blasting, work in the conditions of the need to preserve the contour massif, as well as blasting when making excavations on slopes steepness over 20° and on landslide-prone slopes.

9.3. When developing blasting projects in particularly difficult conditions, a forecast of dynamic effects on the environment and existing buildings and structures should be carried out, as well as an assessment of the environmental consequences of these works.

9.4. When performing blasting operations in particularly difficult conditions, geotechnical and environmental monitoring should be carried out in the zone of possible impact of blasting operations.

9.5. The blasting methods and technological characteristics provided for by the working documentation or the project for the production of blasting operations can be specified in the course of their implementation, as well as based on the results of special experimental and modeling explosions. Changes that do not cause a violation of the design outlines of the excavation, a decrease in the quality of loosening, an increase in damage to structures, communications, land, are specified by a corrective calculation without changing the project documentation. If necessary, changes to the project documentation are made in agreement with the organization that approved it.

9.6. For the storage of explosive materials, provision shall, as a rule, be made for the use of permanent storage facilities for explosive materials. During the construction of enterprises that do not include permanent warehouses of explosive materials, it is necessary to provide them as temporary structures.

Warehouses for explosive materials, special dead ends and platforms for unloading should be provided as temporary structures during the construction of enterprises, if they are not part of them as permanent ones.

9.7. Prior to blasting, the following must be completed:

clearing and leveling of sites, laying out the plan or route of the structure on the ground;

arrangement of temporary access and internal roads, organization of drainage, "frilling" of slopes, elimination of "stabs" and individual unstable pieces on the slopes;

lighting of work sites in case of work in the dark;

device on the slopes of shelves-ledges (pioneer trails) for the operation of drilling equipment and the movement of vehicles;

transfer or disconnection of utilities, power transmission and communication lines, dismantling of equipment, shelter or removal of mechanisms from the danger zone and other preparatory work provided for by the working documentation or the blasting project.

9.8. The size of the blasted soil must comply with the requirements of the project, and in the absence of special instructions in the project, it must not exceed the limits established in a contractual manner by organizations performing earthworks and blasting.

9.9. Deviations from the design outline of the bottom and sides of excavations developed using blasting, as a rule, must be established by the project. In the absence of such instructions in the project, the value of limit deviations, the volume and method of control for cases of explosive loosening of frozen and rocky soils should be taken from Table 6.3, and for cases of excavation by explosion for ejection, they should be set in the project for blasting as agreed between

–  –  –

earthworks and blasting organizations.

9.10. Explosive work at the construction site must be completed, as a rule, before the start of the main construction and installation work, which is established in the PPR.

9.11. When arranging excavations in rocky soils with slopes of 1:0.3 and steeper, as a rule, contour blasting should be used.

9.12. Slopes of profile cuts in rocky soils that are not subject to fastening must be cleared of unstable stones during the development of each tier.

10. Environmental requirements for earthworks

10.1. The environmental requirements for earthworks are set out in the SSP in accordance with applicable laws, standards, and policymakers' documents governing the rational use and protection of natural resources.

10.2. The fertile soil layer at the base of the embankments and in the area occupied by various excavations, before the start of the main excavation work, must be removed in the amount established by the construction organization project and transferred to dumps for subsequent use in reclamation or increasing the fertility of unproductive lands.

It is allowed not to remove the fertile layer:

with a thickness of the fertile layer less than 10 cm;

in swamps, swampy and watered areas;

on soils with low fertility in accordance with GOST 17.5.3.05, GOST 17.4.3.02, GOST 17.5.3.06;

when developing trenches with a top width of 1 m or less.

10.3. The need for removal and the thickness of the removed fertile layer are established in the POS, taking into account the level of fertility, the natural zone in accordance with the requirements of current standards and 9.2.

10.4. Removal and application of the fertile layer should be carried out when the soil is in a non-frozen state.

10.5. Storage of fertile soil should be carried out in accordance with GOST 17.4.3.02.

Methods for storing soil and protecting piles from erosion, flooding, pollution should be established in the construction organization project.

It is forbidden to use the fertile soil layer for the installation of lintels, bedding and other permanent and temporary earthworks.

10.6. In the event that archaeological and paleontological objects are discovered during earthworks, work on this site should be suspended and the local authorities should be notified about this.

10.7. The use of quick-hardening foam to protect soil from freezing is not allowed:

in the catchment area of ​​an open source of water supply within the first and second belts of the zone of sanitary protection of water pipes and water sources;

within the first and second belts of the sanitary protection zone of underground centralized drinking water pipelines;

in territories located upstream of the underground flow in areas where groundwater is used for domestic and drinking purposes in a decentralized manner;

on arable lands, perennial plantations and fodder lands.

10.8. All types of underwater earthworks, discharge of clarified water after alluvium, as well as earthworks in flooded floodplains are carried out according to an agreed project.

10.9. In the course of dredging works or alluvium of underwater dumps in reservoirs of fishery importance, the total concentration of mechanical suspensions must be within the established norms.

10.10. Soil flushing from the decks of dredger vessels is allowed only in the area of ​​the underwater dump.

10.11. Terms of production and methods of underwater excavation should be assigned taking into account the environmental situation and natural biological rhythms (spawning, migration of fish, etc.) in the work area.

–  –  –

11.1. When preparing foundations and arranging foundations, earthwork, stone, concrete and other works must be carried out taking into account the requirements of SP 48.13330, SP 70.13330 and SP 71.13330 and the PPR developed for the facility.

11.2. Works on the construction of bases and foundations without a PPR are not allowed, except for structures of the 4th level of responsibility for their intended purpose.

11.3. The sequence and methods of performing work should be linked to the work on laying underground utilities, building access roads at the construction site and other zero-cycle work.

11.4. When arranging bases, foundations and underground structures, the need for dewatering, compaction and fixing of the soil, fencing the pit, freezing the soil, erecting the foundation using the "wall in the ground" method and carrying out other works is established by the construction project, and the organization of work - by the construction organization project.

If the need to perform the above works arises in the process of developing a PPR or when opening a pit, the decision to perform these works is made by the design and construction organization together with the customer.

11.5. When laying and reconstructing underground utilities, landscaping urban areas and arranging road surfaces, the current rules for the production of work, as well as provisions on the protection of underground and surface engineering structures, must be observed.

11.6. Construction and installation, loading and unloading and special work must be carried out in compliance with safety regulations, fire safety, sanitary standards, environmental requirements and other rules set forth in this set of rules.

11.7. If a discrepancy is found between the actual engineering and geological conditions adopted in the project, it is allowed to adjust the project for the production of works.

11.8. Methods of work performance should not allow the deterioration of the building properties of the foundation soils (damage by mechanisms, freezing, erosion by surface waters, etc.).

11.9. Special foundation works - compaction of soils, embankments and pads, fixing, freezing of soils, ramming of pits and others should be preceded by experimental work, during which technological parameters should be established that ensure the requirements of the project, as well as obtaining benchmarks subject to operational control in the course of work.

The composition of controlled indicators, limit deviations, the scope and methods of control must correspond to those specified in the project.

Experimental work should be carried out according to a program that takes into account the engineering and geological conditions of the site provided for by the project, mechanization tools, the work season and other factors affecting the technology and work results.

11.10. In the process of construction work, incoming, operational and acceptance control should be carried out.

11.11. Quality control and acceptance of work should be carried out systematically by the technical staff of the construction organization and carried out by representatives of architectural supervision and the customer with the involvement of a representative of the construction organization, as well as representatives of the survey and other specialized organizations.

The results of the control should be recorded by an entry in the work log, an intermediate inspection certificate or an acceptance certificate for hidden work, including an acceptance certificate for a separate prepared section of the foundation.

11.12. Upon acceptance of completed works, the conformity of the actually obtained results with the requirements of the project must be established. The specified compliance is established by comparing the design, executive and control documentation.

11.13. In acts of acceptance of foundations drawn up by a geologist of a survey organization, it is necessary:

assess the conformity of the base soils provided for in the project;

indicate the amendments made to the project of foundations and foundations, as well as to the project for the production of works after intermediate inspections of the foundations;

11.14. The following documents are attached to the grounds acceptance certificates:

materials of soil tests performed both in the process of current control of the production of works, and during the acceptance of the foundation;

acts of intermediate inspections and acceptance of hidden works;

work production logs;

working drawings for actual work performed.

11.15. Individual critical structures completed in the course of work should be accepted by the technical supervision of the customer with the preparation of intermediate acceptance certificates for these structures.

11.16. When arranging foundations in pits, the dimensions of the latter in the plan should be assigned according to the design dimensions of the structure, taking into account the design of the fence and fixing the walls of the pit, the methods of drainage and the construction of foundations or underground structures.

11.17. The working drawings of the excavation should contain data on the location of ground or underground structures and communications within its boundaries, the horizons of underground, low-water and high waters, as well as the working water horizon.

11.18. Prior to the start of excavation, the following work must be completed:

breakdown of the pit;

planning of the territory and diversion of surface and ground waters;

dismantling or transfer of ground and underground communications or structures falling into the development spot;

pit fencing (if necessary).

11.19. The transfer (reconstruction) of existing underground utilities and the development of soil in their locations are allowed only with the written permission of the organization responsible for the operation of communications.

11.20. In the process of arranging pits, foundations and underground structures, constant supervision of the state of the soil, fencing and fastenings of the pit, water filtration should be established.

11.21. When excavating pits directly near the foundations of existing structures, as well as existing underground utilities, it is necessary to take measures against possible deformations of existing structures and communications, as well as violations of the stability of the slopes of the pits.

Measures to ensure the safety of existing structures and communications should be developed in the project and, if necessary, agreed with operating organizations.

11.22. Fences and fixings of pits should be carried out in such a way that they do not interfere with the production of subsequent work on the construction of structures. Fastenings of shallow pits should, as a rule, be inventory, and the sequence of their dismantling should ensure the stability of the walls of the pits until the completion of work on the installation of foundation and other structures.

11.23. When developing a pit in water-saturated soils, measures should be taken to prevent slope slippage, suffusion and uplift of the base soil.

If the base is composed of water-saturated fine and silty sands or clayey soils of fluid-plastic and fluid consistency, measures must be taken to protect them from possible disturbances during the movement of earth-moving and transport vehicles, as well as liquefaction due to dynamic effects.

11.24. The shortage of soil at the bottom of the pit is established in the project and specified in the course of work.

A change in the design shortage of soil must be agreed with the design organization.

Accidental overburden in the excavation should be restored with local or sandy soil with careful compaction. The type of filling soil and the degree of compaction must be agreed with the design organization.

11.25. The bases, disturbed during the performance of work as a result of freezing, flooding, sorting out the soil, etc., must be restored in a manner agreed with the design organization.

11.26. Soil excavation in pits or trenches at variable depth

–  –  –

foundations should be ledges. The ratio of the height of the ledge to its length is set by the project, but should be at least 1:2 - with cohesive soils, 1:3 - with non-cohesive soils. The soil must be developed in ways that ensure the preservation of the structure of the soil in the ledges of the base.

11.27. Soils in the base that do not correspond in their natural occurrence to the density and water resistance required by the project should be replaced or additionally compacted using compacting agents (rollers, heavy rammers, etc.).

The degree of compaction, expressed by the density of dry soil, should be specified in the project and should provide an increase in the strength properties of the soil, a decrease in its deformability and water permeability.

11.28. The construction of foundations on foundations from bulk soils is allowed in cases provided for by the project, after preparing the foundation, taking into account the composition and condition of the soils and in accordance with the decision made on the method of filling and compacting them.

The use of embankments of slag and other non-soil materials as foundations is allowed if there are special instructions developed in the project and providing for the production procedure and work technology and their quality control.

11.29. Methods for arranging embankments, pillows, backfills, as well as soil compaction are established in the project and specified in the project for the production of works, depending on the required density and condition of the soils, the scope of work, the available mechanization tools, the timing of the work, etc.

11.30. Backfilling of the sinuses with soil and its compaction should be carried out while ensuring the safety of the waterproofing of foundations, basement walls and underground structures, as well as nearby underground utilities (cables, pipelines, etc.). To prevent mechanical damage to the waterproofing, a protective coating should be used (including from profiled membranes, piece and other materials).

11.32. The installation of foundation and underground structures should be started without delay after the signing of the act and acceptance of the foundation by the commission.

A break between the end of the excavation and the construction of foundations or underground structures, as a rule, is not allowed. In case of forced breaks, measures must be taken to preserve the natural structure and properties of soils, as well as to prevent flooding the pit with surface water and freezing of soils.

11.33. Measures to preserve the natural structure and properties of soils at the base include:

protection of the pit from surface water ingress;

fencing of the excavation and foundation soils with a waterproof wall ("wall in the ground", fencing made of tongue and groove, secant piles, etc.);

removal of hydrostatic pressure by deep drainage from the underlying layers containing water;

exclusion of water inflow into the pit through the bottom;

exclusion of dynamic impacts during excavation of pits by earth-moving machines with the help of a protective layer of shortfall soil;

protection of the base soil from freezing.

11.34. When water enters the pit during the production of water, it is necessary to ensure drainage in order to avoid flooding a fresh layer of concrete or mortar until they acquire a strength of at least 30% of the design.

With a large influx of water, the removal of which can cause the solution to be washed out and the soil to flow into the pit, it is necessary to arrange a backfill pad of concrete laid underwater. The thickness of the pillow is assigned according to the project for the production of works, but not less than 1 m with a water pressure of up to 3 m.

11.35. Enclosed pits for foundations should be carried out in compliance with the following rules:

a) if it is impossible to drain the pit (for the installation of grillages), the excavation of the soil to the design marks should be carried out underwater (airlifts, hydraulic elevators, grabs). To prevent water from entering the bottom of the pit

–  –  –

a concrete backfill layer should be laid using the method of a vertically moved pipe. The thickness of the concrete layer, determined by the calculation of the water pressure from below, must be at least 1 m and at least 1.5 m - in the presence of uneven soil bottom of the pit up to 0.5 m in its underwater development;

b) the top of the pit fences must be located at least 0.7 m above the working water level, taking into account the height of the wave and surge, or 0.3 m above the freezing level. For the working water level (freeze up) in the PPR, the highest possible seasonal water level (freeze up) during the period of performance of this type of work, corresponding to the calculated probability of exceeding 10%, should be taken. At the same time, possible level excesses from the effects of surge winds or ice jams should also be taken into account. On rivers with regulated flow, the operating level is assigned on the basis of information from organizations that regulate flow;

c) it is allowed to pump out water from the excavation enclosure and erection of the grillage after the concrete of the backfill layer acquires the strength specified in the project, but not less than 2.5 MPa.

11.36. The surface of the base, composed of clay soils, should be leveled with a bed of sand (except dusty) with a thickness of 5 - 10 cm. The surface of the sandy base is planned without bedding. Cranes and other mechanisms should be located outside the prepared areas of the base.

11.37. When erecting monolithic foundations, as a rule, preparation of lean concrete is arranged, which makes it possible to lay a screed under waterproofing and prevent leakage of the mortar from the concrete mixture of the concrete foundation.

11.38. With a variable depth of the foundation, its construction begins from the lower marks of the foundation. Then, the upstream sections are prepared and the foundation blocks are laid on the base with preliminary compaction of the filling of the sinuses of the underlying sections or blocks.

11.39. When accepting the prepared foundation, prior to the commencement of work on the installation of foundations, the location, dimensions, elevations of the bottom of the pit, the actual bedding and soil properties specified in the project, as well as the possibility of laying foundations at the design or modified elevation, must be established.

Verification of the absence of violations of the natural properties of the foundation soils or the quality of their compaction in accordance with the design data should, if necessary, be accompanied by sampling for laboratory tests, probing, penetration, etc.

In case of large deviations from the design data, in addition, soil testing with stamps should be performed and a decision made on the need to change the design.

11.40. Verification of the homogeneity and sufficiency of the compaction of soils in natural occurrence or soil pads should be carried out by field methods (probing, radioisotope methods, etc.) and selective determination of the density of dry soil using samples taken from each compacted soil layer.

11.41. If a significant discrepancy between the actual and design characteristics of the foundation soil is established, the need to revise the project and the decision to carry out further work should be made with the participation of representatives of the design organization and the customer.

11.42. When erecting foundations and underground structures, it is necessary to control their depth, size and location in the plan, arrangement of holes and niches, waterproofing and the quality of the materials and structures used. On the device (preparation) of the base and waterproofing, certificates of examination of hidden works must be drawn up.

11.43. Types of control when opening the pit:

observance of the necessary shortfalls in soil, prevention of overshoots and violations of the structure of the soil of the base;

prevention of violation of the soil structure when cutting shortfalls, preparing foundations and laying structures;

protection of base soils from underflooding by underground and surface waters with softening and erosion of the upper layers of the base;

compliance with the characteristics of the exposed soils of the base provided for in the project;

achieving sufficient and uniform compaction of soil pads, as well as backfilling and floor preparations;

–  –  –

the sufficiency of the applied measures to protect the foundation soil from freezing;

compliance with the actual depth of laying and dimensions of structures and the quality of the materials used provided for in the projects.

–  –  –

12.1.1. Methods for driving prefabricated piles: driving, vibration driving, indentation and screwing. Means used to facilitate penetration: leader drilling, removal of soil from hollow piles and shell piles, etc. When preparing for the production of work on pile foundations and sheet piling, the following should be taken into account:

data on the location in the zone of influence of the work of existing underground structures, electric cables, indicating the depth of their laying, power lines, buildings and structures, as well as measures to protect them;

if necessary - preparation of the base for pile and drilling equipment based on the engineering and geological conditions of the construction site and the type of equipment used.

Note. Within the water area, work is allowed to be carried out with waves of no more than one point, if floating cranes and pile drivers with a displacement of up to 500 tons are used, and no more than 2 points with a larger displacement, and jack-up platforms - with waves of no more than 4 points.

12.1.2. When using hammers or vibratory pile drivers for driving piles and sheet piles near existing buildings and structures, it is necessary to assess the danger to them of dynamic effects, based on the effect of vibrations on deformations of foundation soils, technological instruments and equipment.

Note. Assessment of the impact of dynamic impacts on deformations of foundations composed of almost horizontal (slope no more than 0.2), layers of sand sustained in thickness, except for water-saturated dusty ones, can be omitted when driving piles with hammers weighing up to 7 tons at a distance of more than 20 m, when piles are vibrated - 25 m and sheet pile - 15 m to buildings and structures. If it is necessary to drive piles and sheet piles at shorter distances to buildings and structures, measures should be taken to reduce the level and continuous duration of dynamic impacts (piling into leader holes, reducing the height of the hammer, alternating driving of the nearest and more distant piles from buildings, etc.). ) and conduct geodetic observations of the settlements of buildings and structures.

12.1.3. It is not allowed to immerse piles with a cross section of up to 40 x 40 cm at a distance of less than 5 m, sheet piles and hollow round piles with a diameter of up to 0.6 m - 10 m to underground steel pipelines with an internal pressure of not more than 2 MPa.

Pile and sheet piling near underground pipelines with an internal pressure of more than 2 MPa at shorter distances or a larger cross section can only be carried out taking into account the survey data and with appropriate justification in the project.

12.1.4. Additional measures to facilitate the driving of piles and sheet piles (jetting, leader holes, etc.) should be applied in agreement with the design organization in the event of a possible failure of the driven elements less than 0.2 cm or a vibration penetration rate of less than 5 cm/min.

12.1.5. The use of flushing to facilitate pile driving is allowed in areas that are at least 20 m away from existing buildings and structures, and at least twice the depth of pile driving. At the end of the descent, the flushing should be stopped, after which the pile must be additionally loaded with a hammer or vibratory driver until the design failure is obtained without the use of flushing.

12.1.6. Diesel and steam-air hammers, as well as hydraulic hammers, vibratory hammers and pushers can be used to drive piles. The choice of equipment for driving pile elements should be made in accordance with Appendices D and E, based on the need to ensure the bearing capacity provided for by the design of the foundation and the penetration into the ground of piles and sheet piles to the specified design marks, and the sheet pile - deepening into the ground.

The choice of equipment for driving piles with a length of more than 25 m is carried out by calculation using

–  –  –

programs based on the wave theory of impact.

12.1.7. Sections of composite shell piles used to build up submerged shell piles are subject to control docking at the construction site to check their alignment and compliance with the design of the embedded parts of the joints (within the established tolerances) and must be marked and marked with indelible paint for their correct connection (joining) ) at the dive site.

12.1.8. At the beginning of pile driving, 5-20 test piles (the number is set by the project) should be driven, located at different points of the construction site, with the number of blows per meter of immersion recorded. The measurement results should be recorded in the work log.

12.1.9. At the end of pile driving, when the actual failure value is close to the calculated value, it is measured. Failure of piles at the end of driving or after finishing should be measured to the nearest 0.1 cm.

When driving piles with single-acting steam-air hammers, as well as hydraulic hammers or diesel hammers, the last fall should be taken equal to 30 blows, and the failure should be defined as the average value of the last 10 blows in the fall. When driving piles with double-acting hammers, the duration of the last fall should be taken equal to 3 minutes, and the failure should be determined as the average value of the pile penetration depth from one blow during the last minute in the fall.

When indenting piles, record the final indentation force for every 10 cm in the last 50 cm of immersion.

12.1.10. When vibrodriving piles or shell piles, the duration of the last pledge is assumed to be 3 minutes. During the last minute of the pledge, it is necessary to measure the power consumption of the vibratory driver, the immersion speed with an accuracy of 1 cm/min, and the amplitude of the pile or shell pile vibration with an accuracy of 0.1 cm - in order to be able to determine their bearing capacity.

12.1.11. Piles with a failure greater than the calculated one should be subjected to control finishing after they "rest" in the ground in accordance with GOST 5686. In the event that the failure during the control finishing exceeds the calculated one, the design organization must establish the need for control tests of piles with a static load and adjustment of the pile foundation design or its parts.

12.1.12. Piles up to 10 m long, underloaded by more than 15% of the design depth, and piles of greater length, underloaded by more than 10% of the design depth, and for bridges and transport hydraulic structures also piles, underloaded by more than 25 cm to the design level, with their length up to 10 m and underloaded more than 50 cm with a pile length of more than 10 m, but having given a failure equal to or less than the calculated one, should be subjected to an examination to determine the reasons that make it difficult to sink, and a decision is made on the possibility of using existing piles or additional sinking.

12.1.13. During vibration driving of reinforced concrete shell piles and hollow round piles open from below, measures should be taken to protect their reinforced concrete walls from the formation of longitudinal cracks as a result of the hydrodynamic pressure that occurs in the cavity of the pile elements during vibration driving into water or liquefied soil. Measures to prevent the occurrence of cracks should be developed in the PPR and checked during the period of immersion of the first shell piles.

12.1.14. At the last stage of immersion of the shell pile, in order to prevent deconsolidation of the base soil in the cavity of the shell piles, it is necessary to leave a soil core with a height according to the project, but not less than 2 m from the bottom of the shell knife in case of using hydraulic mechanization and not less than 0.5 m when using a mechanical method soil removal.

12.1.15. Before immersion, the steel tongue should be checked for straightness and cleanliness of the lock cavities by dragging it on the stand through a 2-meter template.

Locks and combs of sheet piles when lifting them with a cable must be protected with wooden spacers.

12.1.16. When constructing structures or fences that are closed in plan, the sheet pile should be immersed, as a rule, after its preliminary assembly and complete closure.

12.1.17. Extraction of the sheet pile should be carried out with mechanical devices capable of developing pull-out forces 1.5 times higher than the forces determined during the test extraction of the sheet pile under these or similar conditions.

The speed of lifting the sheet pile during their extraction should not exceed 3 m/min in sands and 1 m/min in

–  –  –

clay soils.

12.1.18. The limiting negative temperature at which immersion of a steel sheet pile is allowed is set by the design organization depending on the steel grade, method of immersion and soil properties.

–  –  –

12.2.1. The device of stuffed piles should be carried out by dipping into the ground steel casing pipes with a lost tip or a compacted concrete plug, removed by hammer blows. The immersion of these pipes is allowed to be carried out by specialized machines equipped with immersion mechanisms of shock, vibration or screwing action.

Pipes are removed after concreting.

The device of bored and bored piles should be carried out using universal grapple, impact, rotary, bucket or screw type units, which, in addition to drilling a well, allow installation of reinforcement cages and concreting, as well as extracting casing pipes.

In the absence of groundwater within the depth of laying piles, their installation can be carried out in dry wells without fastening their walls, and in water-saturated soils with their fastening with retrievable casing pipes, clay (bentonite) or polymer solutions, and in some cases according to the project - under excessive pressure water. In sands and flooded soils, advance drilling is unacceptable.

12.2.2. Dry wells in sand, cased with steel pipes or reinforced concrete shells, as well as open wells drilled in loam and clay layers located above the groundwater level and not having interlayers and lenses of sand and sandy loam, are allowed to be concreted without the use of concrete pipes by the method of free discharge of concrete mix from a height of up to 6 m. It is allowed to lay the concrete mixture by the method of free drop from a height of up to 20 m, provided that positive results are obtained during the experimental verification of this method using a mixture with a specially selected composition and mobility.

In wells filled with water or slurry, the concrete mixture should be laid using the vertically displaced pipe (VPT) method. At the same time, during the concreting process, it is necessary at all stages to control the level of the concrete mixture in the well and the penetration of the concrete pipe into the concrete mixture by at least 1 m.

When concreting dry before and after installation of the reinforcing cage, the well should be surveyed for the presence of loose soil in the face, scree, fallout, water and sludge.

12.2.3. Excessive pressure (pressure) of water in clay soils is allowed to be used for fixing the surface of wells no closer than 40 m from existing buildings and structures.

12.2.4. The level of clay (bentonite) solution in the well during its drilling, cleaning and concreting should be at least 0.5 m higher than the groundwater level (or the water horizon in the water area). effect accompanied by suffusion of near-wellbore soil.

12.2.5. Upon completion of drilling, it is necessary to check the compliance with the project of the actual dimensions of the wells, the marks of their mouths, bottomholes and the location of each well in the plan, as well as to establish the conformity of the soil type of the base with the data of engineering and geological surveys (if necessary, with the involvement of a geologist). If it is impossible to overcome the obstacles encountered during the drilling process, the decision on the possibility of using wells for piling should be made by the organization that designed the foundation.

12.2.6. When installing bored piles, the bottom of the well must be cleaned of loosened soil or compacted by tamping.

Compaction of non-saturated soils should be carried out by dropping a rammer into the well (with a diameter of 1 m or more - weighing at least 5 tons, with a well diameter of less than 1 m - 3 tons).

Compaction of bottomhole soil can also be carried out by vibration stamping, including with the addition of hard materials (crushed stone, hard concrete mix, etc.). The compaction of the soil in the bottom of the well must be carried out to a “failure” value not exceeding 2 cm over the last five

–  –  –

impacts, while the total amount of "failures" of the rammer must be at least the size of the diameter of the well.

12.2.7. Immediately prior to the underwater placement of the concrete mix in each well drilled in the rocky soil, it is necessary to wash off the drill cuttings from the face surface. For flushing, it is necessary to provide water supply under excess pressure of 0.8 - 1 MPa at a flow rate of 150 - 300 m3 / h.

Flushing should be continued for 5 - 15 minutes until the remaining cuttings disappear (which should be evidenced by the color of the water overflowing over the edge of the casing pipe or branch pipe). Flushing must be stopped only at the moment when the concrete mix begins to move in the concrete pipe.

12.2.8. In flooded sandy, subsidence and other unstable soils, concreting of piles should be carried out no later than 8 hours after drilling is completed, and in stable soils - no later than 24 hours. without bringing their bottomhole by 1 - 2 m to the design level and without drilling widenings.

12.2.9. In order to prevent lifting and displacement in terms of the reinforcement cage by the laid concrete mixture and in the process of extracting the concrete or casing pipe, as well as in all cases of reinforcement not to the full depth of the well, the cage must be fixed in the design position.

12.2.10. The volume of the mixture laid before the explosion of the camouflage charge should be sufficient to fill the volume of the camouflage cavity and the pile shaft to a height of at least 2 m. after the explosion.

12.3. Bored piles

12.3.1. Drilling a well when installing bored piles in unstable watered soils should be carried out with washing the wells with clay (bentonite) solution in ways that ensure the stability of the walls of the well.

The parameters of the mud solution must meet the requirements of tables 14.1 and 14.2.

12.3.2. Hardening mixtures and mortars (fine-grained concretes) used for the manufacture of bored injection piles must have a density of at least 2.03 g/cm3, mobility along the AzNII cone of at least 17 cm, and water separation of no more than 2%. It is acceptable to use other similar compositions selected by specialized laboratories, which must meet the requirements of the project.

12.3.3. Filling the well of bored injection piles with concrete mixtures should be carried out through a drilling string or injector pipe from the bottom of the well from the bottom up until the flushing solution is completely displaced and a clean concrete mixture appears at the wellhead.

12.3.4. Pressure testing of the bored pile should be carried out after installing a tampon with a pressure gauge in the upper part of the conductor pipe by injecting a hardening solution through the injector at a pressure of 0.2 - 0.3 MPa for 2 - 3 minutes. Soil compaction around wellbores filled with a solution can also be carried out with pulsed high-voltage discharges using RIT technology (discharge-pulse technology).

12.4. Piles arranged by a continuous hollow auger (CHP)

12.4.1. The installation of bored piles of NPSh should be carried out by screwing a hollow continuous auger into the ground of the base to a predetermined design depth, after which a concrete mixture should be fed into the internal cavity of the auger under pressure. At the same time, the auger must move progressively upwards, lifting the developed soil with its blades, and the resulting well should be gradually filled to the top under pressure with a concrete mixture, into which the reinforcing cage is then immersed.

12.4.2. Drilling rigs and machines for piling according to the FPS method must have control and measuring equipment output to an on-board computer (with a display and a printer) in order to track the speed and verticality of drilling, the amount of torque imparted to the auger, according to given computer programs, the depth of its immersion in the ground, the pressure of the concrete mixture in the cavity of the auger and the volume of concrete laid in the well. All of these data are subject to

–  –  –

prompt display on the computer display, storage in its memory and, if necessary, issuance on printouts.

12.4.3. The process of sinking (drilling) wells should be carried out in one cycle without stopping up to the design level of the pile. When performing drilling operations, the shutter at the lower end of the auger must be closed to prevent water and soil from entering the internal cavity of the auger.

12.4.4. Drilling of wells located at distances less than three of their diameters from the centers of previously manufactured adjacent piles, the concrete strength of which did not reach 50% of the design class, taking into account the actual variation coefficient in accordance with GOST 18105, is not allowed. At distances of more than three diameters, drilling of wells is carried out without restrictions.

12.4.5. The supply of the concrete mixture into the well through the concrete pipelines and the internal cavity of the auger of the drilling machine must be carried out simultaneously with the translational (without rotation) lifting of the auger.

12.4.6. In the presence of water-saturated soils, the excess pressure in the concreting system is established by calculation and, amounting to more than 0.2 MPa, should exceed the pressure of external underground water by 5 - 10%.

12.4.7. The process of concreting the well should be continuous until it is completely filled with concrete mixture to the top. All this time, the auger should gradually move upwards without rotation, and in the concreted system, according to the indications of the on-board computer, the overpressure of the concrete mix is ​​constantly maintained. When the pressure drops to a value of less than 0.2 MPa, the screw lift stops until the specified pressure is restored.

Note. Deviations of the volume of the concrete mixture from the volume of the well, calculated from the actual dimensions, should not exceed 12%.

12.4.8. The reinforcement cage should be installed by immersion in a completely filled with concrete mix and prepared well with a cleaned mouth. Frame acceptance is confirmed in advance (as the possibility of concreting the pile).

“L.V. Skulskaya, T.K. Shirokova ON THE PROBLEM OF COMPARATIVE EFFICIENCY OF PRODUCTION IN INDIVIDUAL SECTORS OF AGRICULTURE The article considers comparative indicators of the results of production of agricultural enterprises and households. The calculated data presented by the authors are...»

«***** Izvestia ***** No. 4 (32), 2013 ZOOTECHNICAL AND VETERINARY COMPLEX UDC 636.2.034(470.45) PRODUCTIVE LONGEVITY OF RECORD-HOLDING COWS A.P. Kokhanov, Doctor of Agricultural Sciences, Professor M.A. Kokhanov, Doctor of Agricultural Sciences, Professor N.V. Zhuravlev, Candidate of Agricultural Sciences, Associate Professor, Volgograd State...»

Agrochemistry named after D.N. Pryanishnikov of the Russian Agricultural Academy, Moscow) Considered the formation and development of the Geographical Network ... "professional education" Saratov State Agrarian University and ... "P.T. Dynamics of the main elements of plant nutrition in the soils of the Soviet Far East // Issues of agriculture in the Far East ... "FEDERATION N 525 COMMITTEE OF THE RUSSIAN FEDERATION ON LAND RESOURCES AND LAND MANAGEMENT N 67 ORDER dated December 22, 1995 ON APPROVAL OF THE BASIC ..." professional education KUBAN STATE AGRARIAN UNIVERSITY FACULTY OF PROCESSING TECHNICS OLOGIY I APPROVE Dean of the Faculty of Processing Technologies _ A. V. Stepovoy "_" _... "State Agricultural Academy named after I.I. Ivanov" Department of Animal Feeding and Technical... "Filippova" "APPROVED" Dean of the Faculty of Engineering Prof._ Ts.Ts. Dambaev "_" _ 2007 Considered and recommended Approved and recommended ... "1 FEDERAL STATE EDUCATIONAL INSTITUTION OF HIGHER EDUCATION "ORENBURG STATE AGRARIAN UNIVERSITY" Department of Sociology and Social Work MASTERING THE DISCIP...»

Notes

1 The timing of geotechnical monitoring should be extended in the absence of stabilization of changes in the controlled parameters.

2 The frequency of fixing the monitored parameters should be linked to the schedule of construction and installation works and can be adjusted (i.e., performed more often than indicated in the geotechnical monitoring program) if the values ​​of the controlled parameters exceed the expected values ​​(including their changes that exceed the expected trends) or identify other dangerous deviations.

3 For unique newly erected and reconstructed structures, as well as during the reconstruction of historical, architectural and cultural monuments, geotechnical monitoring should be continued for at least two years after construction is completed.

4 Fixation of controlled parameters during geotechnical monitoring of the building envelope of a pit with a depth of more than 10 m, as well as at a shallower pit depth in case the controlled parameters exceed the calculated values, must be performed at least once a week.

5 Geotechnical monitoring of the soil mass surrounding the newly erected or reconstructed structure, after the completion of the construction of its underground part and with the stabilization of changes in the controlled parameters of the soil mass and the surrounding buildings, it is allowed to conduct once every three months.

6 In the presence of dynamic effects, it is necessary to measure the level of oscillations of the bases and structures of newly erected (reconstructed) structures and the surrounding buildings.

7 Fixation of changes in the controlled parameters of the state of building structures, incl. damaged, geotechnical monitoring of structures of the surrounding buildings should be carried out, incl. according to the results of periodic visual-instrumental examinations.

8 The requirements of Table 12.1 must be followed, incl. during geotechnical monitoring of structures of the surrounding development located in the zone of influence of the installation of underground utilities, which is determined in accordance with the requirements of 9.33, 9.34.

9 Geotechnical monitoring of newly erected or reconstructed structures on sites of a hazardous category in terms of karst-suffosion must be carried out during the entire period of construction and operation of structures. The term for performing geotechnical monitoring of newly erected or reconstructed structures in areas of a potentially dangerous category in terms of karst-suffosion should be determined in the geotechnical monitoring program, but be at least five years after construction is completed.

Ehhhh... Once again I appeal to the entire geodetic community: LEARN THE MATTER! In SNiPs and GOSTs, everything is described in great detail (albeit clumsily in places).

Gold words! None

It shouldn't even be around!

Now in more detail...

SP 45.13330.2012 "Earth structures, foundations and foundations".

1. We begin to carefully study with section 6.1 "Vertical layout, excavation"(this is how they called the pit here). The most important thing here is table 6.3. Points 1 and 5 (by the way, it will be useful to remember point 9 for improvement).
According to this table, the first 2 tolerances are determined:
- soil surface after excavation. Most often, this is + 10 cm, because digging will be expensive, since you will have to backfill and additionally compact the bottom.
- the surface of the bottom of the pit after final completion ± 5cm.
2. Go to section 17.1 "Consolidation of soils, arrangement of soil cushions". Here everything is clumsy ... However, if you carefully read it, then:
- clause 17.1.1 d) allows us to obtain a definition: crushed stone is a soil material that is rammed into the bottom of the pit when a soil cushion is being constructed. And at the same time it gives an understanding that the "crushed stone foundation" is a kind of construction jargon not defined by the Building Rules.
- paragraph 17.1.5 "Device of soil cushions ..." - here lies the key point in subsection a): "the soil for the construction of a soil cushion should CONDENSE..." According to the laws of physics, with the simultaneous addition of volumes and an increase in the density of the initial volume (we add crushed stone to unrammed soil), the total volume will not change, which means that the height mark determined earlier will not change.
3. The correctness of all conclusions made earlier is confirmed by Appendix H (informative), table H.1, clause 4 b): "The depth of the rammed pit - the deviation from the design mark should not exceed ± 5 cm."

The concept of "sand cushion" does not exist, and it cannot be accepted as a "construction" ... (there is the concept of "sand-gravel mixture", it has the same definition as "crushed stone")

Further accuracy is determined from the logic of the whole pie:

1. A leveling sand-cement screed is laid on the arranged soil cushion (± 5 cm). From this point on, a gradual increase in accuracy begins. Usually, the thickness of the screed is 5 cm in the project. Ideally, where the soil is underestimated by 5 cm - there the thickness of the screed will be 10 cm, and where it is too high - the thickness of the screed will be 0 cm. The average spread of such deviations will give an overrun close to zero. The screed does not carry any bearing capacity - therefore, the actual thickness in a particular place does not matter. The executive geodetic scheme for the screed is not needed, because it is not regulated by the governing documents. Accuracy must be ensured by foremen on the basis of the beacons made by the surveyor (1 by 10-50 meters, as agreed or written in the PPGR). The only thing that the surveyor is obliged to do at this stage is to ensure operational control, Appendix A, clause A.1 of the same joint venture about earthworks.
2. All kinds of waterproofing, etc. are laid. - they do not interest us, since they have a specific thickness, and the foremen and technical specialists will calculate the area themselves.
3. The concrete base of the foundation slab is poured (it is also "concrete"), and only here we begin to talk about sane accuracy and apply the joint venture "Bearing and enclosing structures". In fact, the thickness of the slab depends on the correctness of the pouring of the footing. And the executive is needed not so that the greedy director calculates the overrun, but so that if any jambs come out after pouring the FP, it would be possible to estimate the thickness of the filled slab and the architectural supervision could decide on maintaining the bearing capacity and on the conditions for further construction. Naturally, logic says that the tolerances of SNiP "Bearing and enclosing structures" already apply to the footing.

They say they milk the chickens

Click to reveal...

Thank you for the enlightenment in this area, alas, they explained to me differently at one time, learn forever and ever!