ЖД путь и его компоненты

Railway track and components including

The railway track is designed for the safe movement of trains with the set and promising loads from the rolling stock wheel pairs on rails and speeds of movement.A railway track consists of the upper and lower structures. There are several types of the permanent way: -lying on the subgrade (hereinafter, superstructure); -used on bridges (bridge deck); -located in the tunnels. The upper structure includes the following elements: -rails, -bonds, -sleepers, -ballast, -design for the connection and crossing paths.

To the bottom of the structure are:

-roadbed,

-bridges,

-tunnels.

The purpose of rails to guide the wheels of rolling stock directly and elastically to accept the dynamic load of the wheels and transfer it evenly on the under-rail basis, to perform the role of electrical circuits for signalling current in areas Autolock, and reverse traction current in areas with electric traction.Rails should have the following properties:

-wear resistance;

-fatigue strength;

-high resistance to brittle fracture;

-good weldability;

-high purity of steel;

-good workability;

-low temperature stress;

-the exact geometry and straightness;

-very long service life.

Under-rail supports: cross ties and timbers

The appointment of the under-rail supports:

-to sense the pressure from the rails and transmit it to the ballast prism;

-elastically to process the dynamic impact on the path;

-to maintain constant track width;

-in conjunction with the ballast to ensure the stability of the path in the horizontal and vertical planes;

-ensure the electric insulation of rail lines from each other.

Under-rail support must have:

-strength, stability and durability;

-reliable resistance to longitudinal and lateral displacements in ballast;

-the elasticity and dielectric properties;

-cheap, Nezavisimosty and adaptability.

The main advantages of wooden sleepers and bars are:

-good elasticity;

-simplicity of form, fabrication and operation (transport, shift, attaching the rails, change of gauge, etc.);

-good traction on gravel;

-a relatively small weight (about 70 kg);

-a large electrical resistance.

Disadvantages of wooden sleepers and beams:

-small service life due to decay, mechanical wear and cracking (about 15 years);

-defetsitny high consumption of wood (for 1 km approximately 2 hectares of woodland trees with a diameter of 26-28 cm age 80-100 years);

-the heterogeneity of elasticity of the path length due to the different sizes of sleepers.

Concrete sleepers are cerebroscope, are made of heavy concrete and are reinforced with pre-stressed steel wire or rod reinforcement periodic profile with a diameter of 3 mm. In contrast to the wooden sleepers, the form of which was predetermined by nature, the design of concrete sleepers has given her a more appropriate manner, which improves performance parameters.Due to the fact that the greatest deflections and the pressure on the ballast arise at the ends of the sleepers, the width of her soles is reduced in the middle part up to 250 mm and the ends enlarged to 300 mm. Thickness of the sleepers of variable length – more under the section (the place where there is greatest pressure); in the same place made in the recess for installation of the rail.