Indexed by:
Abstract:
Based on the Biot theory, a 2.5-dimensional finite element analysis model of the track-subgrade-multilayered saturated soil foundation coupling system was established, and a calculation method for the cumulative settlement of the subgrade considering the actual train cyclic load was proposed. The influences of water level rise, train speed, and axle load on subgrade dynamic response and long-term settlement were discussed. Research results show that the amplification effect of water level rise on the soil vibration intensity is not limited to the depth of water level change, but will lead to the increase in the vibration of the entire subgrade and foundation section. This full-section vibration amplification effect increases with train speed. When the water level rises to the inside of the subgrade, significant excess pore pressure will generate inside the subgrade, and the maximum value can reach 27.52 kPa, resulting in a large drop in the effective stress. Then, the stress path of the soil element in the subgrade will approach the failure line. When the water level only rises within the foundation, the cumulative deformation of the subgrade under the train cyclic load is small, and the railway settlement mainly comes from the foundation. When the water level rises to the inside of the subgrade, the cumulative deformation of the subgrade develops rapidly with the loading cycles, which is 19.54 mm after one million times of loading and exceeds the allowable value largely, indicating that the subgrade waterproofing plays a key role in the long-term cumulative settlement control of the railway line. The train speed and axle load affect the cumulative deformation of the subgrade and foundation, and the increase significantly with the axle load of the train. The increase in the axle load has a stronger influence on the cumulative deformation of the subgrade than the foundation. Thus, the effect of axle load on the cumulative deformation should be well considered in the design. © 2023 Chang'an University. All rights reserved.
Keyword:
Reprint 's Address:
Source :
交通运输工程学报
ISSN: 1671-1637
CN: 61-1369/U
Year: 2023
Issue: 4
Volume: 23
Page: 75-91
Affiliated Colleges: