Railway crossings by pipelines. Instructions on the intersection of railway lines of JSC Russian Railways with engineering communications Methodology for thermal engineering calculation of pipelines for underground railway crossings

DEVELOPED by the All-Russian Scientific Research Institute of Railway Transport (VNIIZhT MPS) together with the Main Track Directorate of the Ministry of Railways of Russia

COMPILERS: P.I. Dydyshko, V.V. Sokolov

APPROVED by order of the Main Directorate of Railways of the Ministry of Railways dated March 17, 1995 N TsPI-22

1. GENERAL PROVISIONS

1. GENERAL PROVISIONS

1.1. The requirements of this industry normative document should be followed when designing railway crossings with pipelines for various purposes - heating networks, petroleum product pipelines, oil pipelines, gas pipelines, sewer pipelines, water pipelines of external water supply networks, etc., as well as when designing and implementing measures to eliminate deformations of the railway subgrade, arising at existing intersections with these utilities.

1.2. Transitions of railway lines by pipelines must be provided by overhead laying (on supports or overpasses) or underground - under the roadbed. In this case, the prospect of laying additional (second, third and fourth) main tracks or developing stations should be taken into account.

1.3. To transitions of gas pipelines, oil pipelines, oil product pipelines, etc. Requirements should be made as for sites of a higher category.

1.4. When widening the roadbed for laying additional main tracks or developing stations, the working pipeline at the intersection must be reconstructed or rebuilt (on a new axis) taking into account the corresponding increase in the length of the section of a higher category and, if necessary, subjected to hydrotesting. The protective tube must be extended accordingly.

1.5. In areas where permafrost soils are widespread, pipeline crossings across railways at stages and stations should, as a rule, be carried out by laying them above ground on overpasses. Underground installation in these areas can be provided in foundation soils that do not settle during thawing. In areas with the occurrence of soils that collapse during thawing at a depth of less than 25 m, underground installation is permitted when designing special measures to prevent thawing and settlement based on thermal engineering calculations.

1.6. When designing an underground railway crossing with pipelines in areas with soils prone to frost heaving in the subgrade, it is necessary to perform thermal engineering calculations to prevent unacceptable violations of the temperature regime and frost heaving of these soils. Uneven heaving of the railway track in the longitudinal profile is due to the difference in the depths of freezing-thawing of the soil above the pipeline and outside the zone of its thermal influence. The following types of railway subgrade soils subject to frost heaving should include: clayey (clay, loam, sandy loam); coarse-grained with clay filler with a particle content of less than 0.1 mm in an amount of more than 20% by weight; easily weathered rocks (mudstones, siltstones, marls, shales) in the zone of active weathering; dusty sands when saturated with water; peats and peaty soils.

When underground railway crossings, the working pipeline must be enclosed in a protective pipe (channel, tunnel). Laying the pipeline directly into the ground is unacceptable. Thermal engineering calculations must be used to determine the pipeline laying parameters (laying depth from the base of the rails to the top of the protective pipe and the air temperature in the protective pipe), at which seasonal deformations of the track from frost heaving will be uniform, not exceeding the established maintenance standards for this class of track.

When constructing underground passages or eliminating heaves at existing intersections, the thermal influence of pipelines on frost heaving of railway subgrade soils can be eliminated in the following ways:

- deepening of pipelines by the calculated value;

- reduction of heat loss by thermal insulation of working pipelines;

- removal of excess heat from the protective pipe using natural supply and exhaust ventilation;

- cutting out and replacing heaving soil with draining soil according to calculations throughout the entire seasonal freezing-thawing zone with longitudinal joints; thermal insulation made of polystyrene foam with longitudinal joints.

Each of these methods can be used as an independent measure or in combination with other methods.

1.7. When underground crossing operated railway lines by pipelines, the open excavation method is, as a rule, not allowed.

1.8. When constructing railways over existing pipelines, the working pipeline at the intersection should be enclosed in a protective pipe. Replacement of a protective pipe or service pipeline must be carried out in accordance with the requirements of these standards.

1.9. Pipelines should be located under the railway roadbed outside the station neck at a distance from turnouts and other track intersections of at least 20 m. The minimum distance from pipelines to artificial structures (bridges, culverts, etc.) must be provided in accordance with their degree danger for normal operation of the railway, but not less than 30 m, to the points of connection of suction cables to the rails of electrified railways - 10 m, to contact network supports - 3 m.

1.10. The design of the crossing over the railway must provide the possibility of periodic inspections, routine repairs, shutdown and emptying of pipelines. At crossings of gas pipelines, oil product pipelines, etc. It is necessary to additionally provide devices for warning and blocking train movement in the event of danger.

1.11. When laying underground at stages and stations, the pipeline must be enclosed in a protective pipe (channel, tunnel). At intersections with pipelines transporting explosive or flammable products (gas, oil, etc.), the end of the protective pipe should be located at least 50 m from the bottom of the embankment slope or the edge of the excavation slope, and in the presence of drainage structures - from the outermost drainage structure , and at intersections with water supply lines, sewer lines, heating networks, etc. - at least 10 m on each side.

The vertical distance from the top of the protective pipe (channel, tunnel) to the bottom of the railway rail should be at least 2 m, and when constructing a transition by puncture or horizontal drilling - 3 m. The top of the protective pipe should also be located at 1.5 m below the bottom of drainage structures or the bottom of the embankment. The construction of transitions in the body of the embankment is prohibited.

The depth of pipelines crossing a subgrade composed of heaving soils should be determined by calculation based on conditions under which the influence of heat release or heat flow on the uniformity of frost heaving of the soil is excluded. If it is impossible to ensure the specified temperature regime by deepening the pipelines, ventilation of the protective pipe (channel, tunnel), replacement or thermal insulation of heaving soil at the intersection site, overhead laying of pipelines on an overpass or in a self-supporting case must be provided.

1.12. When crossing railways underground on sections of embankments with a height of more than 6 m, as well as on sloped sections (with a slope steeper than 1:5), the crossing design must include additional measures to ensure the stability of the roadbed. In deep excavations, underground or above-ground crossing of railways by pipelines is selected based on a technical and economic comparison of options.

1.13. Transfer of load to the working pipeline from the weight of the overlying soil and rolling stock is not allowed; the protective pipe and its connections must be waterproof and designed to withstand the weight of the overlying soil and the moving load from a 4-axle freight car of 30 tf/axle. The cross-sectional dimensions of the protective pipe should be taken taking into account the thermal insulation of the working pipelines. When removing excess heat from a tunnel - a protective pipe, its open cross-section must provide the required air flow with natural supply and exhaust ventilation.

1.14. The length of the protective pipe depends on the number of paths in the section where the working grades of the roadbed are crossed, the design of the drainage structures and the location of the wells.

1.15. The distance from the base of the rail to the top of the protective pipe when heaving soils are located in the subgrade is determined by thermal engineering calculations, the methodology of which is given in this document.

1.16. If it is impossible to lower the air temperature in the protective pipe to the required value, natural supply and exhaust ventilation is arranged. The protective pipe is a ventilation tunnel and its ends are adjacent to chambers located on both sides of the roadbed. Supply and exhaust shafts are constructed above the chambers. The supply and exhaust shafts of ventilation systems must communicate only with outside air and the ventilated tunnel. The ventilated tunnel is tightly separated from the channels of the approaching main part of the pipeline by ventilation partitions.

1.17. The distance from the place where the gas pressure decreases to the underground passage of the railway gas pipeline should be determined on the basis of preventing negative gas temperatures at the transition point in the annual cycle.

2. INITIAL DATA FOR DESIGNING RAILWAY CROSSINGS WITH PIPELINES

2.1. The design of pipeline intersections of the subgrade and thermal engineering calculations are carried out based on the following data:

- topographical plan of the crossing area, transverse profile of the roadbed, as well as a diagram of the tracks and placement of various railway devices near the crossing point;

- engineering geological sections along the axis of the pipeline and railway;

- composition, properties and strata of soils of the subgrade and its foundation;

- data on the depth of groundwater and its regime;

- laboratory soil testing;

- long-term monthly average data on air temperature in winter;

- data on the magnitude of uniform frost heaving of the subgrade soils at the transition point.

2.2. At the stage of feasibility study of transition options, it is allowed to accept approximate values ​​for heaving of subgrade soils equal to 20-40 mm for the European part of the Russian Federation and 60-80 mm for roads in the Urals, Siberia and the Far East. During an engineering-geological survey, the amount of uniform track heaving is determined based on the results of two track levelings. The first leveling is carried out in the fall with the onset of negative air temperatures, and the second - during the period of maximum soil freezing. As an exception, the first leveling may be allowed to be carried out during the period of maximum soil freezing, and the second - after complete thawing of the soil before the start of summer track work. The track is leveled along the rail heads at points fixed every 5 m, with their binding to a non-bulging benchmark according to the program of Appendix 1 of the Technical Instructions for eliminating heaves and subsidence of the railway track TsP/4369, approved by the Ministry of Railways on 03/07/86, M., 1987. Length of the leveling section taken equal to 150 m (75 m from the axis of the designed transition in each direction). Its maximum value in the leveling area is taken as the observed value of uniform heaving. The calculated value of this parameter is determined in accordance with the requirements of Technical Instructions TsP/4369.

2.3. The freezing depth of subgrade soils is determined by calculation using nomograms in accordance with the methodology set out in Technical Instructions TsP/4369.

2.4. The groundwater level (GWL) is established in wells with a depth of at least 4.5 m, which are laid on the side of the roadbed and beyond (behind the edge of the excavation, at the base of the embankment). GWL is measured until it is completely established. If necessary, wells will be equipped with a filter for this period.

2.5. Soil samples for laboratory analysis of its physical properties (natural soil moisture, moisture at plastic limits, particle size distribution, density, etc.) are selected according to the program of Technical Instructions TsP/4369. According to the analysis data, soils are classified in accordance with GOST 25100-82 "Soils. Classification".

2.6. After constructing an underground railway crossing with a pipeline at the end of the winter period, the air temperature in the protective pipe is checked for compliance with its calculated value. If the measured value exceeds the calculated value by more than 5%, then additional measures are taken to reduce the air temperature in the protective pipe.

The air temperature in the protective pipe (its surface temperature) is determined at the end of winter using exhaust thermometers placed inside the pipe. The surface temperature of the pipeline can also be measured with thermometers that are installed in the well and placed in a section along the axis of the pipeline.

2.7. Organization of engineering-geological work on the tracks, ensuring the safety of train traffic, safety of people, fencing with signals the places where engineering-geological workings are carried out, etc. are determined jointly by responsible representatives of the design organization and the path distance depending on local conditions and scope of work.

2.8. The project for crossing the pipeline under the railway must be approved by the chief engineer of the railway.

The following materials are submitted for approval:

- general view of the crossing in plan indicating the exact location of the crossing (km, picket, plus);

- longitudinal and transverse profiles along the axes of the pipeline and subgrade with the corresponding engineering geological sections and transition design;

- thermal engineering calculation of a pipeline crossing the roadbed;

Schemes and schedules of work, indicating measures to ensure the safety of train traffic during work.

Agreed-upon projects for crossing pipelines across a railway should be taken into account in special journals indicating the location of the intersection (distance, km, picket, plus) and the main characteristics of the crossing.

Work in the right-of-way can only be carried out after the project has been approved under mandatory technical supervision of the track distance, and, if necessary, of the signaling and communication distance and other linear subdivisions of the railway.

3. METHOD OF THERMAL ENGINEERING CALCULATION OF PIPELINES FOR RAILWAY UNDERGROUND CHANGES

3.1. Characteristics of design climatic regions

3.1.1. The permissible depth of the pipeline and the air temperature in the protective pipe (casing) (Fig. 1), at which seasonal deformations of the track (frost heaving of soils and sediment during thawing) will not exceed the established standards for current maintenance, are determined depending on climatic conditions. The calculated climatic parameter is the long-term average sum of degree-days of negative outdoor air temperatures, °C day. The general railway network of the Russian Federation is divided into the following estimated climatic regions:

Fig. 1 Design diagram of the working pipeline in the protective pipe when crossing the roadbed

Fig. 1 Design diagram of the working pipeline in the protective pipe when crossing the roadbed

The values ​​are determined based on data from the nearest weather station. The period of maximum soil freezing (March-April) is taken as the calculated period.

3.1.2. The temperature of the subgrade soils at various depths from the top of the ballast prism in the calculated climatic regions is established according to the data in Table 1.

Table 1

3.1.3. The calculated temperature of the outside air during the period of maximum soil freezing is taken according to Table 2.

table 2

3.2. Laying depth and air temperature of the protective pipe

3.2.1. The depth of laying pipelines from the base of the rails to the top of the protective pipe is determined depending on the class of the track, the calculated value of heaving and the groundwater level (GWL). For paths of classes 1-3, the permissible values ​​are set according to Tables 3-6, for paths of classes 4-5 - according to Tables 7-10. The upper value of the value in the tables is given for conditions of deep groundwater (the groundwater level is located at a depth of one and a half times the freezing depth), the lower value corresponds to the groundwater level<1,5 .

To model temperature fields and for other calculations, it is necessary to know the temperature of the soil at a given depth.

Soil temperature at depth is measured using exhaust soil-depth thermometers. These are planned studies that are regularly carried out by meteorological stations. Research data serves as the basis for climate atlases and regulatory documentation.

To obtain the soil temperature at a given depth, you can try, for example, two simple methods. Both methods involve using reference books:

1. For an approximate determination of temperature, you can use the document TsPI-22. "Transitions of railways by pipelines." Here, within the framework of the methodology for thermal engineering calculation of pipelines, Table 1 is given, where for certain climatic regions the values ​​of soil temperatures are given depending on the measurement depth. I present this table here below.

Table 1

1. Table of soil temperatures at various depths from a source “to help a gas industry worker” from USSR times

Standard freezing depths for some cities:

The depth of soil freezing depends on the type of soil:

I think the easiest option is to use the above reference data and then interpolate.

The most reliable option for accurate calculations using ground temperatures is to use data from meteorological services. Some online directories operate on the basis of meteorological services. For example, http://www.atlas-yakutia.ru/.

Here you just need to select a settlement, soil type, and you can get a soil temperature map or its data in tabular form. In principle, it’s convenient, but it looks like this resource is paid.

If you know other ways to determine the soil temperature at a given depth, then please write comments.

You may be interested in the following material:

6.31*. Pipeline crossings across railways and highways should be provided in places where roads pass along embankments or in places with zero marks and, in exceptional cases, with appropriate justification in road excavations.

The angle of intersection of the pipeline with railways and roads should, as a rule, be 90°. Laying a pipeline through the body of the embankment is not allowed.

6.32*. Sections of pipelines laid at crossings through railways and highways of all categories with improved coverage of capital and lightweight types must be provided in a protective case (casing) made of steel pipes or in a tunnel, the diameter of which is determined by the conditions of the work and the design of the crossings and must be larger than the outer one pipeline diameter by at least 200 mm.

The ends of the case should be brought out at a distance:

a) when laying a pipeline through railways:

from the axes of the outer tracks - 50 m, but not less than 5 m from the bottom of the embankment slope and 3 m from the edge of the excavation slope;

from the extreme drainage structure of the roadbed (ditch, upland ditch, reserve) - 3 m;

b) when laying a pipeline through highways - from the edge of the roadbed - 25 m, but not less than 2 m from the base of the embankment.

The ends of the cases installed at the sections of transitions of oil pipelines and oil product pipelines through motor roads of III, III-p, IV-p, IV and V categories must be placed 5 m from the edge of the roadbed.

The laying of the pipeline communication cable in the sections where it crosses railways and roads must be carried out in a protective case or separately in pipes.

6.33*. At underground passages of gas pipelines through railways and roads, the ends of the protective cases must have seals made of dielectric material.

At one end of the case or tunnel, an exhaust candle should be provided at a horizontal distance, m, not less than:

from the axis of the extreme track of public railways.......... 40

the same, industrial roads.................................................... 25

from the base of the roadbed...................... 25

The height of the exhaust candle from ground level must be at least 5 m.

6.34*. The depth of sections of pipelines laid under the railways of the general network must be at least 2 m from the base of the rail to the upper part of the protective case, and in recesses and at zero marks, in addition, at least 1.5 m from the bottom of the ditch, tray or drainage .

The depth of pipeline sections laid under roads of all categories must be at least 1.4 m from the top of the road surface to the upper part of the protective casing, and in recesses and at zero marks, in addition, at least 0.4 m from the bottom of the ditch, drainage ditch or drainage.

When laying a pipeline without protective casings, the above depths should be taken to the upper generatrix of the pipeline.

The burial of pipeline sections under highways on the territory of compressor stations and oil pumping stations is accepted in accordance with the requirements of SNiP II-89-80*.

6.35. The distance between parallel pipelines in the sections of their transitions under railways and roads should be determined based on soil conditions and work conditions, but in all cases this distance must be no less than the distances accepted for underground laying of the linear part of main pipelines.

6.36. The intersection of pipelines with the rail tracks of electrified transport under switches and crosses, as well as in places where suction cables are connected to the rails, is not allowed.

6.37. The minimum horizontal clear distance from the underground pipeline at the points of its passage through the railways of the general network should be taken, m, up to:

switches and crossings of the railway track and joining points

suction cables to electrified iron rails

roads........................................................ ........... 10

switches and crosspieces of the railway track with heaving

soils........................................................ ......... 20

pipes, tunnels and other artificial structures on iron

roads........................................................ ........ thirty

1.1. The requirements of this industry standard
document should be used as a guide when designing transitions
railways pipelines for various purposes - thermal
networks, petroleum product pipelines, oil pipelines, gas pipelines,
sewer pipelines, external water supply networks
water supply, etc., as well as in the design and implementation
measures to eliminate deformations of railway earthen
canvases arising in places of existing intersections with these
engineering communications.
1.2. Crossing railway lines with pipelines is necessary
be provided by overhead installation (on supports or
overpasses) or underground - under the roadbed. At the same time, it should
the prospect of laying additional (second, third and
fourth) main tracks or station developments.
1.3. To the transitions of gas pipelines, oil pipelines,
oil product pipelines, etc. demands should be made on both
areas of higher category.
1.4. When widening the roadbed for laying additional
main tracks or station developments working pipeline in place
intersections must be reconstructed or rebuilt (on a new
axis) taking into account the corresponding increase in the length of the section of increased
category and, if necessary, subjected to hydrotesting.
The protective tube must be extended accordingly.
1.5. In areas of permafrost, transitions
pipelines through railways at stages and stations
should be carried out, as a rule, by overhead laying along
overpasses. Underground installation in these areas can be
provide foundations in soils that do not settle during thawing.
In areas with the occurrence of subsidence when thawing soils on
depth less than 25 m, underground installation is permitted if
designing special measures to prevent
thawing and precipitation based on thermotechnical calculations.
1.6. When designing an underground railway crossing
pipelines in areas buried in the subgrade
soils subject to frost heaving, it is necessary to carry out
thermal engineering calculations to prevent unacceptable violations
temperature regime and frost heaving of these soils. Uneven
heaving of the railway track in the longitudinal profile is caused by
difference in the depths of freezing-thawing of the soil above
pipeline and outside the zone of its thermal influence. To the susceptible
frost heaving of railway subgrade soils
the following types should be included: clayey (clay, loam,
sandy loam); coarse-grained with clay filler when maintained
particles less than 0.1 mm in size in an amount of more than 20% by weight;
easily weathered rocks (mudstones, siltstones, marls,
shales) in the zone of active weathering; dusty sands
saturating them with water; peats and peaty soils.
At underground railway crossings, the working pipeline
must be enclosed in a protective pipe (channel, tunnel). Laying
pipeline directly into the ground is unacceptable. Thermotechnical
by calculation it is necessary to determine the parameters of the pipeline laying
(laying depth from the base of the rails to the top of the protective pipe and
air temperature in the protective pipe), at which seasonal
deformations of the path from frost heaving will be uniform, not
exceeding the established content standards for this class
ways.
When constructing underground passages or eliminating abysses on
existing intersections, the thermal influence of pipelines on
frost heaving of railway subgrade soils can
be eliminated in the following ways:
- deepening of pipelines by the calculated value;
- reduction of heat loss by thermal insulation of workers
pipelines;
- removal of excess heat from the protective pipe using
natural supply and exhaust ventilation;
- cutting out and replacing heaving soil with drainage soil
calculation in the entire seasonal freezing-thawing zone with
longitudinal mates; thermal insulation made of polystyrene foam with
longitudinal joints.
Each of these methods can be used as
a stand-alone event or in combination with other methods.
1.7. During the underground passage of operating railways
pipeline lines, the open method of penetration, as a rule, is not
allowed.
1.8. When constructing railways over existing ones
pipelines, the working pipeline at the intersection should be
enclose in a protective tube. Replacing the protective pipe or worker
pipeline must be carried out in accordance with the requirements
real standards.
1.9. Pipelines should be located under the subgrade
railway outside the station neck at a distance from the switch points
transfers and other crossings of the path at least 20 m. Minimum
distance from pipelines to artificial structures (bridges,
culverts, etc.) must be provided in
in accordance with the degree of their danger for normal operation
railway, but not less than 30 m, to the points of connection
suction cables to the rails of electrified railways
- 10 m, to the contact network supports - 3 m.
1.10. The design of the railway crossing should
ensure the possibility of periodic inspections, routine repairs,
shutting down and emptying pipelines. At gas pipeline crossings,
oil product pipelines, etc. additionally needed
provide warning and traffic blocking devices
trains in case of danger.
1.11. For underground laying at stages and stations
the pipeline must be enclosed in a protective pipe (channel,
tunnel). At intersections with pipelines transporting
explosive or flammable products (gas, oil, etc.), end
the protective pipe should be located at least 50 m from the base
slope of an embankment or slope edge of an excavation, and in the presence of drainage
structures - from the outermost drainage structure, and on
intersections with water pipelines, sewer lines, thermal
networks, etc. - at least 10 m on each side.
The vertical distance from the top of the protective pipe (channel,
tunnel) to the base of the railway rail should not be taken
less than 2 m, and when constructing a crossing using a puncture method or
horizontal drilling - 3 m. The top of the protective pipe should
be located, in addition, 1.5 m below the bottom of the drainage pipes
structures or the base of an embankment. Arrangement of transitions in the body of the embankment
prohibited.
Burying pipelines crossing the roadbed,
composed of heaving soils should be determined by calculation,
based on conditions under which the influence of heat generation is excluded
or heat drain on the uniformity of frost heaving of the soil. At
inability to provide the specified temperature due to
deepening of pipelines, ventilation must be provided
protective pipe (channel, tunnel), replacement or thermal insulation
heaving soil at the intersection site, overhead laying
pipelines on a trestle or in a self-supporting case.
1.12. At underground crossings of railways in sections
embankments more than 6 m high, as well as on sloped areas (with
slope steeper than 1:5) the intersection design should include
additional measures to ensure the sustainability of earthen soil
canvases. In deep excavations, underground or above-ground crossing
railway pipelines are selected based on
technical and economic comparison of options.
1.13. Transfer of load to the working pipeline from weight
overlying soil and rolling stock is not allowed, protective
the pipe and its connections must be waterproof and designed to withstand
perception of the weight of the overlying soil and moving load from 4
axle freight car 30 t/axle. Cross section dimensions
protective pipe should be taken into account the design of the thermal
insulation of working pipelines. When removing excess heat from
tunnel - protective pipe, its live cross-section should provide
required air flow with natural supply and exhaust
ventilation.
1.14. The length of the protective tube depends on the number of paths on
section of transition of working marks of the roadbed, structure
drainage structures and location of wells.
1.15. The distance from the base of the rail to the top of the protective pipe at
The location of heaving soils in the subgrade is determined
thermotechnical calculation, the methodology of which is given in this
document.
1.16. If it is impossible to lower the air temperature in
the protective pipe is provided with a natural
supply and exhaust ventilation. The protective pipe is
ventilation tunnel and its ends are adjacent to the chambers,
located on both sides of the roadbed. Above the cameras
supply and exhaust shafts are constructed. Supply and exhaust shafts
ventilation systems must communicate only with outside air and
ventilated tunnel. The ventilated tunnel is tightly separated from
ventilation channels of the approach main part of the pipeline
partitions.
1.17. Distance from the place where the gas pressure decreases to
underground passage of the railway gas pipeline should be designated
based on avoiding negative gas temperatures in the area
transition in the annual cycle.

2. INITIAL DATA FOR DESIGN
RAILROAD CROSSINGS BY PIPELINES

2.1. Design of subgrade intersections
pipelines and thermal engineering calculations are made based on
data:
- topographic plan of the transition area, transverse profile
roadbed, as well as path diagrams and placement of various
railway devices near the crossing point;
- engineering geological sections along the axis of the pipeline and
railway;
- composition, properties and strata of soils of the subgrade and
its foundations;
- data on the depth of groundwater and its regime;
- laboratory soil testing;
- long-term average monthly data on air temperature in
winter period;
- data on the magnitude of uniform frost heaving of soils
roadbed at the transition point.
2.2. At the stage of feasibility study of options
transition it is allowed to accept approximate heaving values
subgrade soils equal to 20-40 mm for the European part
Russian Federation and 60-80 mm for roads in the Urals, Siberia and Dalniy
East. During engineering-geological survey the value
uniform path heaving is determined based on the results of two
leveling the path. The first leveling is carried out in the fall with
the onset of negative air temperature, and the second - in
period of maximum soil freezing. As an exception, maybe
be allowed to carry out the first leveling during the period
maximum freezing of the soil, and the second - after complete
thawing of the soil before the start of summer track work. The path is leveled
along the rail heads at points fixed at 5 m intervals, tying them
to a non-bulging benchmark according to the program of Appendix 1 of the Technical
instructions for eliminating heaves and subsidence of the railway track
TsP-4369, approved by the Ministry of Railways on 03/07/86, M., 1987. Length
leveling area is taken equal to 150 m (75 m from the axis
designed crossing in each direction). As an observed
the values ​​of uniform heaving take on its maximum value
at the leveling site. The calculated value of this parameter
determined in accordance with the requirements of the Technical
instructions TsP4369.
2.3. The freezing depth of subgrade soils is determined
calculation using nomograms in accordance with the methodology set out in
Technical instructions CPU/4369.
2.4. The groundwater level (GWL) is established in wells
with a depth of at least 4.5 m, which are laid on the side of the earthen
canvas and beyond (behind the edge of the recess, at the base
embankments). GWL is measured until it is completely established. At
If necessary, the wells will be equipped with a filter for this period.
2.5. Soil samples for laboratory analysis of its physical properties
properties (natural soil moisture, humidity within
plasticity, particle size distribution, density, etc.) are selected
according to the program of Technical instructions TsP-4369. According to analyzes
soils are classified in accordance with GOST 25100-82 “Soils.
Classification".
2.6. After the construction of the railway underpass
pipeline at the end of the winter period, compliance is checked
air temperature in the protective pipe to its calculated value. If
the measured value exceeds the calculated value by more than 5%, then
are taking additional measures to reduce air temperatures in
protective pipe.
The air temperature in the protective pipe (its temperature
surfaces) are determined at the end of winter with exhaust thermometers,
placed inside the pipe. Pipe surface temperature
can also be measured with thermometers that are installed in
well, laid in a section along the axis of the pipeline
2.7. Organization of engineering and geological work along the way,
ensuring the safety of train traffic, safety of people,
fencing of engineering-geological production sites with signals
workings, etc. determined jointly by those responsible
representatives of the design organization and the travel distance in
depending on local conditions and volumes of work.
2.8. The pipeline crossing project under the railway should
be agreed upon by the chief engineer of the railway. On approval
present the following materials:
- general view of the transition in plan indicating the exact location
transition (km, picket, plus);
- longitudinal and transverse profiles along the axes of the pipeline and
roadbed with the corresponding engineering-geological
cuts and transition design;
- thermal engineering calculation of the pipeline crossing the earthen
canvas;
- diagrams and schedules of work production indicating activities
to ensure train safety during production
works
Coordinated projects for crossing pipelines through the railway
the road should be taken into account in special journals indicating the location
intersection (distance, km, picket, plus) and main characteristics
transition.
Work in the right-of-way can only be carried out after
approval of the project under mandatory technical supervision
travel distances, and, if necessary, signaling distances and
communications and other linear divisions of the railway.