The sleeper is an important part of the track structure. It bears various forces from the rail, and elastically transmits the force to the track bed, while effectively maintaining the gauge, direction and position of the track. The force of the sleeper is extremely complex, and the force it bears includes vertical, lateral and longitudinal forces, while the structure of the track bed supporting the sleeper is complex, and the characteristics of random changes in the support conditions change the force state of the sleeper at any time. This premise determines The complexity of sleeper design. The sleeper is made of wood, also known as sleeper, anti-corrosion wooden sleeper is also called oil-filled sleeper. Wooden sleepers are divided into three types: ordinary wooden sleepers, turnout sleepers (fork sleepers) and bridge sleepers (bridge sleepers).
Disadvantages of wooden sleepers: the geometric dimensions of the track are not easy to maintain, and are susceptible to mechanical damage, decay, wear, and short service life. This is also due to the level of production technology; due to the different types and parts of wood, its strength and elasticity are not completely consistent. Under the action, the track will be uneven, and the dynamic effect of the wheel and rail will be increased. The polyethylene plastic sleeper has the advantages of convenient handling, light weight and low cost, and its bearing capacity is strong, and its moisture-proof and anti-corrosion performance is better than that of wooden sleepers. It is a new type of engineering plastic that can replace wood with environmental protection and long service life.