The specific nature of railway construction is the linear nature of the work, i.e. Construction is carried out sequentially along the length of the future path, starting from its initial point and up to the final one. Railway-construction work in its implementation depends on a variety of conditions - topographic, geological, hydrological, weather and climate and other natural conditions.
The construction of the railway includes such stages as excavation and construction of the upper structure of the road. Excavation involves the formation and consolidation of the roadbed, together with its drainage and measures to prevent its freezing. The construction of the upper structure of the track includes the formation of a ballast prism, the laying of the under-rail base - sleepers, the attachment of fastening and the connection of rails.
In addition, railway construction requires the construction of man-made structures such as pipes for draining water, drainage trays, fast flows, overpasses, etc., as well as the construction of intersections with road and other railways, deaf intersections and switch points.
The basis for railway construction is the formation of a roadbed. The earthen canvas is a complex of engineering soil structures that serve as the basis for the upper structure of the road. The earth canvas perceives the load from the rail-grating, ballast and rolling stock, evenly distributing it to the underlying natural soil.
Construction of the upper track structure
- The laying of track links is assembled, which is assembled at production bases. The links stacked in stacks (packages) are transported on special platforms. During the installation of the rail-grille, the bags are pulled into the area of the load-lifting track crane.
- The rail grille is assembled at the place of production: the sleepers are laid out, the rails are piled on them and they are mounted.
Each of the ways has its pros and cons. The advantage of the first option is the speed of production at the construction site. However, the beginning of work with this method is possible only from the point of abutment, since the laying is carried out by cranes on the rail track. Also, this method has a higher cost compared to the second, because The assembly site of the rail-grille can be far away from the installation site.
The second method, in addition to the low cost, allows you to mount the rail-grille from any place of the road being built, because Laying is carried out by car cranes. The disadvantage of this option is an increase in the period of work.
Further, along the laid path, ballast is delivered to the place of work in hopper dispensers or gondola cars. It is unloaded on the move when the train moves with a specified speed. After the backfilling of the rail grate, it is lifted onto the ballast. The layered ballasting is completed by filling the sleepers, which makes it possible to bring the ballast prism to the required dimensions.
Each cycle of track works also includes the operation of straightening the track, during which the position of the track gauge is adjusted to the standards that meet the safety requirements for driving at specified speeds. After laying the way, it is planned to run the train by train. In addition, the finishing and finishing works are performed before the site is handed over to the permanent operation.
The structure of the upper structure of the track must be strong, stable, stable, wear-resistant and economical in order to ensure safe and smooth movement of trains at maximum speeds under any operating conditions.