Introduction

The instructor introduces the topic of the lesson, which is the lower structure of railway tracks. They also provide instructions on how to construct and maintain railway tracks.

• The topic of the lesson is the lower structure of railway tracks.

• The main instruction for constructing and maintaining railway tracks is CP 544.

• Temporary instruction 31 54 P was introduced on December 30, 2015, and it applies to all Russian Railways (RZD) tracks from July 1, 2016.

• The description of earthworks elements will be provided in the video description.

Earthwork Elements

This section describes what earthwork elements are and their importance in railway track construction.

Purpose of Earthwork Elements

• Earthwork elements serve as a foundation for laying down upper track structures.

• They consist of engineered structures such as embankments, cuttings, drainage systems, and retaining walls.

• Their primary function is to ensure safe train movement with specified loads at designated speeds.

Maintenance of Earthwork Elements

• Regular maintenance is necessary to ensure that all earthwork elements remain in good condition.

• Monitoring, diagnosis, and repair work should be carried out regularly to prevent any issues from arising or worsening over time.

Track Maintenance

This section discusses how track maintenance should be carried out throughout the year.

Year-Round Maintenance

• Track maintenance should be performed year-round along every stretch of track including those under repair.

• It includes monitoring, diagnosis, repair work as well as identifying potential problems before they occur.

Surface Planning

• Proper surface planning ensures that water does not accumulate anywhere on the track surface but instead flows freely away from it through drainage systems or other means.

Types of Earthwork Elements

This section describes the different types of earthwork elements used in railway track construction.

Types of Cross-Sections

• There are three main types of cross-sections: embankments, cuttings, and level crossings.

• Embankments have two slopes and a flat top surface.

• Cuttings have two slopes and a flat bottom surface.

• Level crossings have a flat top surface that is either above or below ground level.

Individual Cross-Sections

• Individual cross-sections are designed for specific projects based on detailed geological surveys and engineering calculations.

• They are typically used for complex projects with challenging geological or topographical conditions.

Overview of Railway Track Construction

This transcript provides an overview of the construction of railway tracks, including the dimensions and specifications for various elements such as the main platform, ballast prism, embankment, and drainage structures.

Main Platform

• The main platform is the part of the track that experiences the most dynamic vibrations from moving trains and is subject to seasonal weather fluctuations.

• The width of the main platform is determined by factors such as the number of tracks and soil types.

• According to instruction 2288 p., for first and second category lines, the size of the main platform is 7.6 meters; for third category lines it's 7.3 meters; for fourth category lines it's 7.1 meters.

• For two-track lines, minimum width is 11.7 meters.

Ballast Prism

• The ballast prism is a non-draining part of the track used to stabilize slopes and support track components.

• It should have a cross-sectional trapezoidal shape with a height ranging from 0.15 to 0.2 meters depending on whether it's a one or two-track line.

Embankment

• The embankment consists of artificial side slopes that form a transverse profile for stability.

• Slope steepness depends on soil type and height above ground level.

• For heights up to six meters, slope steepness should be one-and-a-half times; upper parts should be one-to-one-and-a-half times steeper than lower parts.

Drainage Structures

• Drainage structures are used to collect surface water runoff from tracks and adjacent areas.

• Surface water runoff flows down through drainage channels located at each end of ballast prisms into ditches or culverts below ground level.

Elements of Railway Track Construction Continued

This transcript continues the overview of railway track construction, focusing on additional elements such as berms, subgrade, and water drainage structures.

Berm

• The berm is a slightly sloping or horizontal area at the base of the embankment that separates it from adjacent areas.

• It should be at least three meters wide and seven-and-one-tenth meters wide on the side of future tracks.

Subgrade

• The subgrade is the natural ground surface beneath the ballast prism.

• It's used to provide stability for track components and support for workers and equipment during maintenance activities.

Water Drainage Structures

• Water drainage structures are used to collect and remove water from tracks and adjacent areas.

• Surface water runoff flows down through drainage channels located at each end of ballast prisms into ditches or culverts below ground level.

Introduction to Earthwork

In this section, the speaker introduces earthwork and discusses how to prevent soil erosion.

Earthwork Profile

• The profile of earthwork includes a large excavation that is repeated throughout the length of the road.

• The main function of the excavation is to prevent soil erosion by increasing water flow and reducing sedimentation in drainage channels.

• The excavation can be reinforced with stone paving, slab coverings, or other strengthening structures.

Elements of Earthwork Profile

This section covers the different elements that make up an earthwork profile.

Main Platform

• The main platform is a part of the earthwork profile that has dimensions corresponding to those of the road.

• Its primary function is to support the road structure.

Drainage Prism

• A part of the main platform used for water drainage.

• It helps drain water from the surface and prevents it from accumulating on the road.

Slope Crest

• The line where the slope intersects with the main platform.

• It can be reinforced with a slope crest ditch or a ditch between slopes for water drainage.

Ditches

• Used for draining surface water from elements such as longitudinal channels.

• They are 60 cm deep and 40 cm wide at their base.

Berms

• Berms are added features not present in cross-sectional profiles for embankments.

• They are triangular or trapezoidal structures made out of soil placed along embankment slopes.

• Their purpose is to protect against erosion and provide additional stability.

Bankets and Banket Channels

This section covers bankets and banket channels, which are important components in preventing soil erosion in earthworks projects.

Bankets

• A banket is a triangular or trapezoidal structure made out of soil placed along the top edge of an embankment slope.

• It is used to protect against erosion and provide additional stability.

• The banket should be located at least 1 meter from the slope crest with a slope of 0.02 to 0.04 in the opposite direction from the drainage prism.

Banket Channels

• A channel that runs along the banket for water drainage.

• They are small, measuring only 30 cm deep and wide at their base.

Cavalier and Drainage Ditches

This section covers cavaliers and drainage ditches, which are important components in preventing soil erosion in earthworks projects.

Cavalier

• A trapezoidal-shaped embankment made out of soil placed along the top edge of an embankment slope.

• It should be located at least five meters from the slope crest with a slope of 0.02 to 0.04 in the opposite direction from the drainage prism.

• Its purpose is to protect against erosion and provide additional stability.

Drainage Ditches

• Used for draining surface water from elements such as longitudinal channels.

• They are small, measuring only 30 cm deep and wide at their base.

Hillside Ditch

This section covers hillside ditches, which are important components in preventing soil erosion in earthworks projects.

Hillside Ditch

• A ditch that runs along a hillside for water drainage.

• It has dimensions similar to those of regular drainage ditches (60 cm deep and wide).

Width of Earthwork Strip

This section covers how to determine the width of an earthwork strip based on project requirements.

Width of Earthwork Strip

• The width of an earthwork strip is determined by the project's construction plan and the location of all structures, including water supply systems, production buildings, and service facilities.

• The width should be at least 10 meters from the edge of the track to the boundary of the earthwork strip.

Snow Protection

This section covers how to protect against snow accumulation in earthworks projects.

Snow Protection

• Protective forest plantations are created on sections of road that are prone to snowdrifts.

• Permanent snow fences are built where protective forests cannot be established.

• A strip of land measuring at least 50 meters wide is allocated for this purpose.

Marking Earthwork Strips

This section covers how to mark earthwork strips for safety purposes.

Marking Earthwork Strips

• Special markers are installed along the boundary of an earthwork strip at intervals not exceeding 250 meters.

• At each bend in the boundary line, a marker indicating the direction and distance to the