The card is intended for rational organization labor of workers involved in the installation of a layer of synthetic non-woven material (dornite) at the base roadbed(on a grip 50 - 100 m long) with rolling out the material into longitudinal direction.

Designation:	KTP 6.03.1.2002
Russian name:	Installation of a layer of synthetic non-woven material (dornite) at the base of the subgrade with rolling out the material in the longitudinal direction
Status:	no expiration date set
Replaces:	KT 10.5.1.90
Date of text update:	05.05.2017
Date added to the database:	01.09.2013
Effective date:	01.01.2002
Approved:	01.01.2002 Rosavtodor
Published:	State Enterprise Tsentrorgtrud Rosavtodor (2002)
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MINISTRY OF TRANSPORT OF THE RUSSIAN FEDERATION

STATE ROAD SERVICE
(ROSAVTODOR)

CENTER
ORGANIZATION OF LABOR AND ECONOMIC
MANAGEMENT METHODS
(TSENTRORGTRUD)

COLLECTION OF CARDS
LABOR PROCESSES FOR CONSTRUCTION,
REPAIR AND MAINTENANCE OF HIGHWAYS

Work process map

Layer device
made of synthetic non-woven material (dornite)
at the base of the subgrade
with rolling out the material in the longitudinal direction

KTP-6.03.1-2002

Second edition, revised and expanded

(Issue 6)

Moscow 2002

Cards labor processes designed to improve the organization of labor of workers engaged in construction, repair and maintenance highways.

The maps determine the progressive technology of work, rational use working hours, technological sequence of work performance based on advanced techniques and labor methods.

Maps can be used in the development of organizational and technological documentation for the construction, repair and maintenance of highways (PPR and others), work planning, as well as in educational purposes in the training of highly qualified workers.

A collection of maps of labor processes prepared by engineers A.I. Anashko, E.V. Kuptsova, T.V. Insurance.

Responsible for the release A.A. Morozov.

. Scope and effectiveness of the card

The name of indicators

Unit

Value of indicators

according to TE, EniR

Output per 1 person-day

Labor costs for constructing 100 m 2 layers of synthetic non-woven material (dornite)

Note: Labor costs include time for preparatory and final work - 2% and rest - 13%.

Using the card will increase labor productivity by up to 5 - 6%.

2. Preparation and conditions for performing the process

Name

Bulldozer on a T-130 tractor

Roller DU-29 (D-624)

Folding knife

Shovel

Fastening brackets

Typical fencing and safety signs

M 1 - brings the unit into working position, performs leveling and lays it in accordance with the design profile. At idling carries out partial compaction of the embankment.

Compacting the soil of the base of the embankment in 6 passes along one track

M 2 - brings the unit into working position and performs compaction with 6 passes of the roller with a turn on the embankment.

Preparing dornite rolls for rolling

D 1, D 2, D 3 - bring the dornite roll to the rolling site. At the ends of the grip, where the dornite is rolled out, beacon markers are placed.

Rolling out rolls in the longitudinal direction, cutting sheets, fastening with staples

D 1, D 2 - rolls are rolled out manually across the entire width of the base. D 3 - after rolling out the first meters, the edge part of the web is secured with 3 staples, and during further rolling - after 1.5 - 2 m. At the end of the gripping, the web is cut off (D 3) from the roll with a knife and turned 180° (D 1, D 2), continuing rolling in the opposite direction, overlapping with an overlap of at least 15 cm.

Quality control of work performed, correction of defects

D 1, D 2, D 3 - after rolling out all the dornite, the quality of the laid layer and the quality of joining of the panels are checked by visual inspection. Move to the next capture.

Development of soil of group II with a movement of 20 m for backfilling of dornite

M 1 - brings the unit into working position and develops, moves and unloads soil onto the underlying layer of dornite with an empty return to the face.

Leveling the soil with a bulldozer

Soil compaction in 6 roller passes along one track

Non-woven synthetic material (NSM) is a non-woven needle-punched fabric, which is made by weaving synthetic polymer fiber. It is not subject to wear and rot. Due to the combination of excellent indicators, the material is convenient to use in most areas of human activity: construction works, road construction, pipeline laying, Agriculture, design and more.

The NSM is capable of performing four functions at once:

Filtration. Due to its unique structure, the canvas prevents the passage of sand and earth particles into the pores of the material, preventing the possibility of silting;
Drainage. Prompt drainage of water is ensured, which increases the performance of the drainage system;
Reinforcing. Like a geogrid, it takes on the soil load and can partially withstand tensile stress;
Dividing. NSM serves separating layer, eliminating mixing of the top layer and base. At the same time, the thickness of the top layer does not change.

Advantages of the material

NSM is widely popular today due to:

Durability;
Environmental friendliness. The canvas is not affected chemical elements, thanks to which harm to people and nature can be avoided;
Strength. The material has high level resistance to mechanical stress and puncture. Tensile threads allow the web to be lengthened, which eliminates the possibility of damage during installation;
Impact resistance natural factors. Does not cause debate, siltation and does not rot. Resistant to ultraviolet rays, exposure to acids, alkalis and organic matter. The material is not affected in any way by fungi and bacteria;
Ease of installation. NSM is supplied in the form of easy-to-transport rolls, which, if necessary, can be cut into two parts using an ordinary saw. hand saw. The material can also be cut with scissors and a knife;
Economical. With all its advantages, NSM is relatively inexpensive, which is the main reason for its use in many areas of life.

Areas of use

Is a filter in drainage systems;
Men at work. Used for styling railway track, highway. It is assigned a reinforcing function; Can also be used for garden paths.
Agriculture. NSM material can protect crops from weeds, and the soil from contamination by microorganisms and drying out.
In construction. Used as waterproofing layer and a protective layer in the roof and foundation;
Strengthening the banks and slopes of reservoirs;

NSM characteristics table

Active

Approved by the Ministry of Railways on May 3, 1988.

The Technical Instructions set out the requirements for the design and calculation of anti-deformation structures made of non-woven material, laid to eliminate track subsidence, intense disorders of the rail track, slope slips, as well as to prevent the formation of ballast troughs and beds on the main platform of the roadbed and washouts. The basic provisions on the organization and technology of work during the construction of these structures are given.

For engineering and technical workers of track facilities.

Responsible for the release: P.I. Dydyshko, V.V. Sokolov

Editorial Head V.G. Peshkov

Editor L.P. Topolnitskaya

Issued by order of the USSR Ministry of Railways

INTRODUCTION

In conditions of increasing freight intensity and loads from rolling stock on the rails and increasing train speeds, the intensity of track disturbances increases, which adversely affects the carrying capacity railways.

The stability of the railway track largely depends on the roadbed, which is composed of clay soils for approximately 70% of its length. Under the combined influence of moving loads and climatic factors, the roadbed in these places deforms unevenly. The main area (the interface between ballast materials and clay soils) is often affected by ballast troughs and beds. As a rule, the intensity of path disorders in terms of level and profile in these areas is increased. In some cases (approximately 1% of the total network length), track subsidence occurs, which is accompanied by uneven subsidence and shifts of the rail track, liquefaction of clay soil with splashes from under the sleepers, and squeezing out masses of this soil onto the surface of the ballast prism. They intensify when the soil thaws and rains fall. In favorable engineering-geological conditions, deformations of the under-rail foundation can occur in places of increased dynamic impact of moving loads (switches, leveling spans of continuous track, etc.), as well as in heavily clogged areas.

In modern operating conditions, the possibility of providing “windows” in the movement of trains to carry out work to strengthen the roadbed and the track as a whole with high traffic loads is limited. This forces us to reduce volumes as much as possible. earthworks and move on to using artificial materials that have the necessary properties in anti-deformation structures.

For thermal insulation, foam plastic is used, which prevents seasonal freezing - thawing of clay soils; for hydraulic insulation, a polymer film is used, which prevents the infiltration of precipitation. Thermal and waterproofing coatings are laid within the ballast prism. The requirements for their design are set out in the Technical Instructions for eliminating the causes and subsidence of the railway track, TsP/4369.

Non-woven synthetic material, which is currently finding increasing use in the construction and operation of structures for various purposes in our country and abroad, is capable of separating and reinforcing soils, draining and removing water. This material is made from synthetic fibers (waste, secondary raw materials or primary from the melt of polymers), which are mechanically joined together using needle-punching machines, where special needles entangle them in a layer. To produce materials, fibers from various polymers (polyester, polyamide, polypropylene, etc.) are used, the chemical and biological resistance of which ensures their service life in the ground for several decades. The use of natural fibers is excluded, since they are short-lived when working in the ground.

Among the most important properties nonwovens include the following:

ability to retain small soil particles (filter property);

high water permeability;

high mechanical tensile strength combined with elasticity and elongation ability;

Manufacturability of application (low consumption per unit area, ease of transportation, installation and connection).

Possessing the specified set of properties, the nonwoven material performs one of its functions - the role separating layer. The stress-strain state of the soil that has developed under the combined influence of loads and climatic factors changes after laying the nonwoven material. This layer prevents the manifestation of residual deformations of the soil, since the freedom of movement of individual particles is limited. They cannot pass through the material. This prevents the interpenetration of large particles into the clay soil and small particles into the draining soil. The shift of individual layers, aggregates or soil particles in the interlayer zone is difficult.

Reinforcing function of the material is that it is able to withstand tensile forces and increase the bearing capacity of the soil foundation reinforced with this material. In this case, the stresses in the soil mass are redistributed. The layer, working like a membrane, transfers some of the stresses, leveling them to a certain extent, from more loaded places to less loaded ones.

In the role reverse filter the material prevents mechanical suffusion, i.e. removal of small soil particles by water flow. In this case, in the direction of water movement in front of the layer of nonwoven material, as a result of re-sorting of particles, an additional natural soil return filter is formed.

The performance of non-woven fabric as drainage layer(drainage function) is possible due to its high water permeability along the canvas. For example, when the material is located on soil with a low filtration coefficient, the flow of infiltrating sediments, having reached the layer of this material, will begin to move along it. Some of the water will go down into the ground, but part of it will change its movement in the direction of less resistance and will be diverted away from the soil in need of protection.

These functions appear depending on the type of deformation being eliminated separately or, as is most common, together.

Non-woven material is used to eliminate and prevent track subsidence, intense disorders of the rail track, float of slopes of embankments and excavations, erosion of flooded slopes, uneven settlement of embankments in swamps, silting of drainages for various purposes, etc. In some cases, this material is used in combination with a waterproofing film.

Some of the deformations practically or cannot be eliminated without the use of non-woven materials, or their elimination requires significant labor and material costs, as well as long interruptions in train traffic. Such deformations include subsidence of the track with the squeezing of liquefied soil onto the surface of the ballast prism, slopes floating due to surface waterlogging, washing out of soil from under the covering slabs of bank protection structures and flooded embankments, etc. Non-woven material is indispensable in those structures where, when using draining soil, it is necessary to perform work with high, often difficult to achieve accuracy (installation of a return filter in drainage and other structures).

The use of non-woven material coatings instead of traditional structures reduces the cost of eliminating and preventing deformations. At the same time, labor costs for maintaining the roadbed and the track as a whole are reduced, its major renovation or construction, the capacity of the lines increases, and significant savings are achieved.

These Technical Instructions contain basic provisions for obtaining initial data for design, conditions for the use of nonwoven materials, necessary requirements and recommendations for the construction of anti-deformation structures from these materials, as well as the organization and technology of work.

The instructions were developed based on the results of experimental and pilot production use of non-woven material on railways, analysis of foreign experience, laboratory tests and calculations.

Technical instructions were developed by VNIIZhT, KhabIIZhT, KhIIT, VNII of Transport Construction together with the Main Track Directorate of the Ministry of Railways and the Northern Railway.

1. GENERAL PROVISIONS

1.1. These Technical Instructions are intended for use by employees of services and track distances, track machine stations, engineering-geological bases and track survey stations, design organizations and construction departments in the appointment, design and implementation of measures to strengthen the under-rail base and other elements of the railway roadbed using non-woven materials .

1.3. Reinforcement of the roadbed with the use of non-woven materials in areas with track subsidence, drift of slopes of embankments and excavations, water erosion and other types of deformations in difficult engineering-geological conditions is carried out according to projects developed on the basis of the technical specifications of the track service, which indicates a list of deformable sections according to data operational observations and technical passport of the track distance.

Work to eliminate intensive disorders of the rail gauge in level and profile using non-woven material is provided for in projects for major and medium track repairs. The repair estimate documentation includes the specified work. The feasibility of use and specific areas for laying non-woven material are established on the basis of operational data on the condition of the track, labor costs for its maintenance, rail output, wear of superstructure elements and other indicators.

Together with the laying of non-woven material, the projects provide for the reconstruction or construction of new drainage systems to ensure the drainage of infiltrated sediments from the non-woven material covering.

1.4. Laying of coverings made of non-woven material is carried out as follows: independent work or together with major (medium) track repairs, providing for maximum mechanization using track, general construction earth-moving and special machines designed for repairing the roadbed. The work is carried out by track machine stations, including specialized ones, separate specialized columns of these stations and track distance teams.

1.5. The purpose of coverings made of non-woven material must be justified by a technical and economic comparison with other methods of eliminating deformations of the subgrade and strengthening the under-rail base (layout of the main site, arrangement waterproofing coating and etc.).

1.6. The main characteristics and location of laid non-woven material coverings, as well as changes in the nature and size of deformations after laying, are reflected in the established manner in the relevant forms of technical passports of track distances.

2. INITIAL DATA FOR DESIGN

2.1. The initial data for the design of anti-deformation structures using non-woven material on operating lines is obtained during an engineering-geological survey, which is carried out on the basis of the technical specifications of the track service.

2.2. During an engineering-geological survey to develop a project to eliminate deformations of the sub-rail base (track subsidence, intense disturbances of the rail track in level and profile on an unstable subgrade, uneven heaving of homogeneous soils), an inspection of the site is carried out, characteristic signs of deformations are recorded and an instrumental survey is carried out. By drilling, digging or testing pits with sampling, the composition, composition and condition of the soils of the subgrade are determined. In this case, at least five points of the under-rail base (along the axis of the track, under both rails with their outside and at a distance of 20-40 cm from the ends of the sleepers) in the sleeper box and under the sleeper, the configuration of the surface of the clay soil is established on the main platform of the roadbed. Determine the presence and depth of groundwater, sources of local soil moisture and other hydrogeological conditions. The required volumes and procedure for conducting engineering-geological surveys are established in accordance with the requirements of the Technical Instructions for eliminating heaves and subsidence of the railway track, TsP/4369.

2.3. Initial data for the design and calculation of coatings using non-woven material in order to eliminate deformations of embankment slopes are obtained in the required volumes in accordance with the requirements of the Temporary Guidelines for calculating the stability of exploited embankments and designing counter-banks (M.: Transport, 1979. 32 pp).

When examining embankments with slope slips, it is advisable to drill exploratory transverse slits along its entire cross-section to delineate the interface between the drainage soils of the ballast layer and the plume and the clayey soils of the embankment along its entire cross-section. The slots are laid in the deformation area and beyond.

2.4. During the engineering-geological examination of deforming slopes of excavations, a geodetic survey of transverse profiles is carried out, the nature of soil bedding in the slope parts, hydrogeological conditions, the size and nature of deformations, as well as the depth of the zone of soil softening under the influence of natural weathering processes are determined, the composition, condition and properties of the soils of each varieties. Soil strength indicators are established in accordance with the requirements of the regulatory and technical document specified in clause 2.3.

2.5. The fastening of flooded slopes is designed on the basis of initial data obtained in accordance with the requirements of the Manual on the survey and design of railway and road bridge crossings over watercourses (TsNIIS, Glavtransproekt. M.: Transport, 1972. 272 p.).

3. CONDITIONS FOR APPLICATION OF NON-WOVEN MATERIALS FOR REINFORCING THE SUB-SITE

3.1. Non-woven material is used to eliminate deformations on operating lines.

Conditions for using nonwoven material depending on the type and causes of deformation during various types roadbed are given in Table 1.

3.2. To strengthen the subgrade, non-woven material is used, which must meet the following requirements:


Strip width, mm
Thickness, mm
Weight 1 m, g
Breaking load, kgf, for a strip 5 cm wide in the direction:
longitudinal
transverse
Elongation at break, %, in the direction:
longitudinal
transverse
Water permeability (filtration coefficient), m/day

3.3. In anti-deformation structures of railway subgrades, it is possible to use a non-woven material that meets the stated requirements and is manufactured according to technical specifications"Needle-punched fabric for road construction- Dornit. Technical specifications" TU 21-29-81-81*, type 1, which is intended for elevated roads bearing capacity. The use of material types 2 and 3 to reinforce railway subgrades is not permitted.
________________
* Specifications mentioned here and further in the text are not given. For more information please follow the link. - Database manufacturer's note.

In addition, it is allowed to use nonwoven materials produced according to other technical conditions, including imported ones, if they meet the above requirements, as well as waste materials from chemical fiber factories non-woven fabrics for filtering viscose solutions, washed and sewn into strips.

Test methods for nonwoven material are set out in the specified TU 21-29-81-81.

Table 1. Conditions for the use of nonwoven materials in anti-deformation structures


Type of deformation	Type and elements of the subgrade	Causes of deformation	Anti-deformation measures
A. Elimination of deformations on operating lines
Planting tracks with squeezing liquefied clay soil through the ballast layer during thawing and intense rains; disorders of the rail track in level and profile with the formation of splashes due to the penetration of clay particles from the main platform into the ballast layer		Insufficient bearing capacity of clay soils as a result of increased moistening by infiltrating moisture in the presence of ballast troughs and beds on the main site	Laying a covering of non-woven material over the entire width of the subgrade; when the depth of the ballast beds is more than 0.5 m - laying a covering of non-woven material in combination with a waterproofing film; installation of closed drainages, deepening of ditches and trays below the bottom of ballast beds
Disorders of the rail gauge in level and profile with the formation of splashes as a result of clogging, mainly in the area of joints, leveling spans, turnouts, crossings	Excavations, nullahs and embankments composed of clayey, drainage and rocky soils, tunnels and bridges with ballast running	Insufficient load-bearing capacity of the contaminated ballast layer when moistened by precipitation	Laying a coating of non-woven material within the ballast prism under the rail-sleeper grid
Uneven heaving of the subgrade composed of homogeneous clay soils	Recesses and voids in clayey soils, embankments of clayey soils	High uneven moistening of heaving soils by infiltrating moisture with ballast troughs and beds of different depths on the main site	Laying non-woven material in combination with a waterproofing film over the entire width of the subgrade on top
Slope slips and track settlements on unstable embankments	Embankments of clay soils on a solid foundation	Increased moistening of the upper layers of soil within the main site and slopes by infiltrating moisture, stagnation and accumulation of moisture in ballast depressions on the main site, in cracks and depressions on slopes	Laying non-woven material coverings within the main site and slopes on potentially unstable areas of embankments, including in combination with the installation of counter-banquets; laying a combined covering of non-woven material and waterproofing film on embankments with active manifestation of deformations
Washouts, drifts and slides of excavation slopes	Excavations in homogeneous clayey, as well as in heterogeneous (clayey, draining) soils	Increased soil moisture during thawing and due to infiltrating precipitation, groundwater reaching the surface	Laying a covering of non-woven material on the slope of an excavation with anchoring it at the top in the behind-the-slope part
Destruction of strengthening of flooded slopes, erosion of slopes	Embankments, dams, counter-banquets	Soil removal under the influence of high flow velocities, waves, rise and fall of levels
Erosion of the banks and bottom of watercourses near artificial structures, as well as erosion of the slopes of embankments or cones	Embankments at junctions with artificial structures and at river edges	Water erosion	Laying non-woven material with riprap instead of fascines, mattresses, etc.
Uneven settlement of embankments in swamps	Mounds on swamps	Insufficient bearing capacity of the embankment base	Construction of berms with laying of non-woven material under them
Silting of drainages for various purposes	Drainage systems in excavations, ground zeros and embankments	Mechanical suffusion of soil	Application of non-woven material as a return filter
B. Prevention of deformation
Possible subsidence of the track with the formation of ballast troughs and beds on the main platform, squeezing out liquefied clay soil through the ballast layer	Recesses and voids in clayey soils, embankments of clayey soils	Insufficient bearing capacity of clay soils with a typical ballast prism without a protective layer	Laying non-woven material together with a drainage pad on the main subgrade area
Possible damage to strengthening flooded slopes	Embankments, dams, counter-banquets	Removal and suffusion of soil	Laying non-woven material under the external reinforcement as a return filter

3.4. Parameters for the determination of which there are no regulatory documents are established on non-standard models that take into account the operating mode of non-woven material in railway track structures. These parameters are determined in accordance with the test procedure outlined in the annex.

3.5. When installing a combined coating (see Table 1), a waterproof film is used together with non-woven material, for example, grade B polyvinyl chloride film with a thickness of 0.23 mm (GOST 16272-79).

The film used must have the following characteristics:


Width, mm
Thickness, mm
Breaking tensile stress, kgf/cm
Elongation at break, %
Vapor permeability in 24 hours, g/m
Brittleness temperature, °C

4. ELIMINATION OF TRACK SETTLEMENTS AND RAIL TRACK DISORDERS ON UNSTABLE AREAS OF THE SUBSTRATE.

4.1. To eliminate track subsidence and disorders of the rail track in level and profile, a non-woven material coating is laid on unstable sections of the subgrade when the depth of ballast troughs and beds is less than 0.5 m. The design of this coating in cross section on single-track and double-track sections of railways is shown in Fig. 1 and 2.

Fig.1. Schemes for laying a coating of non-woven material to eliminate track subsidence and rail track disorders in level and profile on unstable sections of the roadbed within embankments

Fig.1. Schemes for laying a coating of non-woven material to eliminate track subsidence and rail track disorders in level and profile on unstable sections of the roadbed within embankments:

A- on a single-track line; b, c 1 - non-woven material; 2 - ballast; 3 - clay soils

Fig.2. Schemes for laying a coating of non-woven material to eliminate track subsidence and disorders of the rail track in level and profile on unstable sections of the roadbed in excavations

Fig.2. Schemes for laying a coating of non-woven material to eliminate track subsidence and disorders of the rail track in level and profile on unstable sections of the roadbed in excavations:

A- on a single-track line; b, c- on a double-track line with one track and two tracks; 1 - non-woven material; 2 - ballast; 3 - clay soils; 4 - drainage; 5 - tray

The non-woven material is placed at a depth of at least 0.2 m below the bottom of the sleepers () on the surface of ballast materials cut and leveled with a slope of at least 0.04 to the field side.

If the distance from the top of the ballast prism to the main platform of the subgrade made of sandy loam and loam with a yield boundary is less than 0.7 m along the axis of the track, and for heavier loams and clays - less than 1 m, then after laying the non-woven material covering, an additional lift is made ways to achieve the specified values.

The covering is laid across the entire width of the subgrade on top. On double-track sections, in the absence of deformations on the adjacent track, it is possible to install covering only on one track.

The bottom of ditches, trays, closed drainages in recesses and zero places should be located 0.2 m below the coating and 0.15 m below the bottom of the ballast beds. If these conditions are not met, the drainage systems are rebuilt, lowering the level of their bottom.

To eliminate track subsidence and track disturbances under turnouts, the coating must be of variable width. The edges of the covering are located behind the ends of the transfer bars by at least 0.9 m (Fig. 3, A). It is laid 0.2 m below the bottom of the beams with a slope of at least 0.02.

Fig. 3. Diagram of a non-woven material coating for eliminating track subsidence

Fig. 3. Diagram of a non-woven material coating for eliminating track subsidence:

A- on turnouts; b- on station tracks; 1 - non-woven material; 2 - drainage; 3 - ballast; 4 - clay soils

When constructing a covering under turnouts and on station tracks, a shallow drainage with a longitudinal slope of at least 0.03 is laid along it between the tracks, the outlet from which is carried out by transverse drainage (see Fig. 3, a, b). To do this, use pipe filters or a “blind” drain with a diameter of at least 15 cm, which is made of crushed stone wrapped in non-woven material. The bottom of the drainage should be below the edge of the covering.

In the same way, if necessary, water is drained from between tracks on stretches in curved sections of the track.

When using crushed stone of normal size in the ballast layer, a layer of sand, asbestos ballast or small crushed stone of a fraction of 10-25 mm with a thickness of 5-10 cm is laid on the non-woven material.

When eliminating track subsidence, separate strips of nonwoven material in the coating are placed across the track, i.e. the length of these strips should be equal to the width of the coating. The strips must overlap each other by at least 0.2 m. When eliminating disorders of the rail gauge in level and profile on unstable sections of the roadbed, it is allowed to place strips of non-woven material along the track with a mutual overlap of at least 0.2 m.

In difficult engineering-geological conditions with intense track subsidence with squeezing out liquefied soil through ballast, non-woven material in the coating can be laid in two layers. In this case, crushed stone of normal size can be directly laid on non-woven material.

The section covered with non-woven material must cover the length of the section of the track with apparent deformations by at least 30 m on each side. The minimum length of the covered section can be 30 m.

It is not allowed to lay a covering of non-woven material to eliminate track subsidence and disorders of the rail track in level and profile on unstable sections of the subgrade only within the rail joints.

4.2. To eliminate those considered in at this point track deformations in areas where the depth of ballast troughs and beds on the main platform of the roadbed is more than 0.5 m, a combined coating of non-woven material and waterproofing film should be used. The film is placed between two layers of nonwoven material (Fig. 4).

Fig.4. Diagram of the installation of a combined coating of non-woven material and waterproofing film when eliminating track subsidence

Fig.4. Diagram of the installation of a combined coating of non-woven material and waterproofing film to eliminate track subsidence:

1 - non-woven material; 2 - waterproofing film; 3 - new ballast; 4 - uncut ballast; 5 - clay soil

The covering is placed at a depth of at least 0.3 m from the bottom of sleepers or transfer bars (when laid under turnouts).

Crushed stone of normal size can be laid directly on the combined coating.

Strips of non-woven material and waterproofing film are spread along the path, starting from the bottom side, which ensures water drainage from the coating in the transverse direction.

The remaining requirements for the installation of the coating are observed in accordance with clause 4.1.

5. ELIMINATION OF DISORDERS OF THE RAIL GAUGE AT THE LEVEL AND IN THE PROFILE WITH THE FORMATION OF SPLASHES IN CLOGGED AREAS

5.1. Non-woven material is placed within the ballast prism at a depth of at least 20 cm from the bottom of the sleepers (Fig. 5, A).

Fig.5. Schemes for the design of a coating made of non-woven material when eliminating disorders of the rail gauge in level and profile in areas with splashes from clogging

Fig.5. Schemes for the design of a coating made of non-woven material when eliminating disorders of the rail gauge in level and profile in areas with splashes from clogging:

A- on hauls; b- within turnouts; 1 - cleaned ballast layer; 2 - non-woven material; 3 - the ballast layer is contaminated; 4 -drainage

Under the layer of non-woven material, the crushed stone must be cleared of debris to a depth of at least 10 cm in order to ensure the most complete and rapid removal of infiltrating moisture into this layer. Laying non-woven material on unplanned rollers of cleaned crushed stone in under-rail sections remaining after the operation of the ballast cleaning machine is not allowed. This surface must be level.

When using crushed stone of normal size in the ballast layer, a layer of fine crushed stone or sand 5-10 cm thick is poured onto the non-woven material. This layer can be omitted if the non-woven material in the coating is laid in two layers: placement of the second layer is allowed within the under-rail sections of the width at least 0.8 m under each of them (for example, by appropriately overlapping two lanes in these places).

5.2. The operation of straightening and tamping machines during the laying of the coating until a layer of ballast 20 cm thick is created under the sole of the sleepers is not allowed, since in this case the coating will be torn apart (VPR) or collected under the rail-sleeper grid (RSO).

5.3. The accumulation of clogging above the layer of non-woven material will occur in the usual way, however, the drainage conditions in this case are more favorable, since the path and time of moisture filtration will be reduced compared to conventional design ballast prism without non-woven material. Rapid drainage of water down and to the side will prevent weeds from becoming waterlogged, which increases the load-bearing capacity of the ballast layer.

Non-woven material is laid under the rail-sleeper grid to a width of at least 4.5 m. Within the turnouts, the width of this covering should be variable and exceed the length of the transfer bars by m on each side (Fig. 5, b).

In areas with a stable subgrade, where disturbances in the rail gauge in level and profile with the formation of splashes occur due to weeds, a continuous covering is installed; at the same time, in some justified cases, it is allowed to construct a covering only under joints, and in sections of continuous track - under leveling spans. On turnouts, it is allowed to lay material in the areas of the crosspiece and frame rail that are most susceptible to dynamic effects from moving loads. The edges of the covering must be at least 2 m from the joints.

To drain water in the transverse direction, the layer of non-woven material is brought up to the slope of the ballast prism on hauls, and on station tracks and turnouts - to shallow drainage. This drainage is arranged in accordance with the requirements of clause 4.1.

5.4. The coating within the abutments of bridges, as well as the spans of reinforced concrete bridges running on ballast, is laid at the depth indicated above, reaching the sides of the ballast troughs (reverse walls of the abutments). Longitudinal drainage of water is carried out using drains, which are placed along these sides. In this case, drains can be made of non-woven material, which is rolled into a roll from a strip approximately 1 m wide.

6. APPLICATION OF COATING FROM NON-WOVEN MATERIAL AND WATERPROOFING FILM TO ELIMINATE HEAVENS

6.1. The conditions for using this coating are set out in Table 1. Uneven heaving in homogeneous soils manifests itself in this case as a result of the existing (or ongoing) subsidence of the track. The ballast troughs and beds of varying depths that arise during these subsidences lead to increased uneven moistening of cohesive soils that are infiltrated with moisture. Due to its properties, non-woven material cannot be used independently to eliminate heaves. It is used for this purpose in conjunction with a waterproofing film, which retains infiltrating precipitation.

6.2. The construction of a coating made of non-woven material and a waterproofing film to eliminate heaving under the conditions under consideration is carried out in accordance with the requirements set out in clause 4.2.

7. ELIMINATION OF SLOPE SLIDDS AND PATH SETTLEMENT ON UNSTABLE EMBARKES ON A SOLID FOUNDATION

7.1. On unstable areas of embankments, a coating of non-woven material or a combined coating of non-woven material and waterproofing film is laid, depending on the nature of the manifestation of deformations.

7.2. A coating made of non-woven material can be used if the embankment slopes do not slide, but the following signs of deformation appear:

precipitation, including one-way precipitation, and shifts of the rail track, usually associated with the period of ground thawing and intense rains;

cracks at the ends of the sleepers, on the sides and slopes;

subsidence of roadsides, soil uplifts on slopes;

change in steepness and outline of slopes.

The use of such a coating is most appropriate for increasing the stability of the embankment in its upper part, which has a height (counting from the top) of 6-8 m, with a thickness of the potentially unstable soil mass on the slope up to 1.5-2 m. In this part of the embankment, they are usually located , unstable ballast trains and it is usually not possible to ensure its stability by filling counter-banquets.

7.3. The covering consists of a non-woven material laid over the surface of the slope and a layer of drainage soil poured on top. The non-woven material is anchored in the upper part outside the potentially unstable mass, placing it in a ballast prism under the rail-sleeper grid. Under these conditions, the joint work of the nonwoven material and the soil is ensured due to the forces of friction and adhesion between them. Shearing forces, which are an integral part of gravity, in the presence of a coating must overcome not only those holding forces that develop on the surface of possible displacement (friction and adhesion forces), but also the tear resistance of the interlayer. The pavement parameters that ensure the stability of the embankment with a given coefficient are determined by calculation. In this case, three conditions must be met simultaneously: sufficient adhesion of the nonwoven material to the underlying soil; tensile strength of the material; reliability of anchoring in the upper part.
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