Subway sleeper is one of the components of railway track. It is mainly connected directly at the bottom of the track when it is used. To a certain extent, it can stabilize the position of the track and prevent the danger caused by the displacement of the track when the train is passing. It can also distribute the pressure generated by the train on the average over the ballast. It makes the train run more steadily.
Engineering Characteristics of Subway Sleepers
1. The construction of Metro railway sleepers requires seamless line speed laid at one time, and the speed standard for checking traffic is 80 km/h at one time. It requires high smoothness and stability of the line and high construction technology requirements.
2. Subway crosstie improves the original construction technology of monolithic ballast to a certain extent, and concrete pours monolithic ballast at one time. There is no process of pouring piers.
3. Difficulties in the construction of train sleepers: the line is mainly on the viaduct, the highest point is more than 20 meters, and it is located in two roads, shopping malls, residential areas, highway traffic intersections and other traffic congestion areas. The materials and equipment needed for laying the line need to be suspended to the bridge for operation, and it is difficult for materials to enter and bridge. The working surface is limited, the reverse transportation on the bridge is heavy, and the safety protection under the bridge is difficult.
4. The construction progress of the units under the concrete sleepers line of Metro is inconsistent. There are 12 Construction breakpoints, and the length of construction breakpoints is 200-400 M. It makes the construction of track engineering can not work continuously. It can only reverse the construction tools and machinery after the construction, which increases the labor intensity.
In the operation of Metro crossties, mobile contact welded rail cars are used to weld 25m rails directly into unit rail joints on the line. Rail cars and flat cars are used to weld rail equipment. The heavy vehicle, large slope and small curve radius make the operation of welded rail more difficult.
The track shock absorber fasteners, short crossties, DTVI 2 fasteners and short sleepers of Metro sleepers are not centralized enough on the line, and there are many segments, which cause a large number of supporting tools to be reversed. Because of the long construction time span, cold construction in winter and high temperature construction in summer, different measures must be taken to ensure the construction quality.