The Research Of Bearing Space Of Steel Rail On Elevated Integrated Ballast Bed Of Urban Rail Transit

ABSTRACT: Urban track transit is the aortic in urban traffic, and it is the primary way to solve the problem of traffic jam in large cities. Compared with road traffic, it has many advantages such as large traffic volume, less pollution, no level crossing with the urban road, prompt, security and comfort. So track traffic has won the favor of many countries in 20th century.In contrast with main-line railway, urban track traffic aims for urban and suburb transportation. It has many advantages such as large traffic volume, light axle-load, low speed, high rate of traffic flow, concentrated passenger flow, decentralized traction, short distance in the whole range and single operation. At the same time, the security, low noise, long life, Less maintenance of the track structure is required. Different design Standards should be taken because of the characteristics of the urban track traffic, so the reasonable standards, technical security, investment economic targets can be assured. The Support spacing of rail is one of the main design standards. It plays an important part in keeping track gauge, bearing the load from the rail and delivering it to ballast. It is also important for strengthening longitudinal rigidity,lateral rigidity and resistance force. Furthermore, it can help maintain longitudinal and lateral stability of the track. In the present subway standard, the number of sleepers has been specified according to the mechanical characteristics of the parts of track structure, the domestic practical experience of subway operation, the number of sleepers in national railway and foreign subway. In our country, the number of 1600 per kilometer is commonly used. However, in foreign cities, the support spacing is not less than 700mm. The sleeper spacing is relatively small in our country, and the waste can be caused.In this paper, aiming at the characteristics of urban track traffic, research has been done mainly on support spacing of rail on integrated ballast bed of viaduct. Calculation and analysis have been done on the influence on mechanical characteristics of track structure caused by different sleeper spacing. According to the finite element theory, with the use of finite element analysis software"Ansys", the space model of track structure of integrated ballast bed on bridge has been established and the following research has been done: the stress and displacement of rail and bridge in different conditions of support...