Vertical Track Irregularity Caused by Subgrade Settlement and Its Design Criteria for High-speed Railway
Vertical track irregularity mostly comprises short -wave rail surface erosion caused by vari -ous reasons and long-wave permanent deformation caused by subgrade settlement. In this study, first,the development of subgrade settlement due to repeated train traffic is investigated. A unified constitutive model of geomaterials is developed to describe the residual deformation of ground soil and embankments granular fill under cyclic loadings. Thereafter,a full-scale physical model testing with dynamic loading up to 10ton was carried out in the laboratory on a railway model with 15 m * 5m * 6m dimensions,using harmonic periodic wave to simulate one wheelset loadings. Results show that acceleration of track structure and dynamic stresses of subgrade vary significantly with excita -tion frequency. And there exists a critical frequency and peak frequency ,corresponding to the maximum growth rate and maximum value respectively. Subgrade settlement under different excitation frequencies occurred in the physical model is predicted , using the proposed numerical computation model. Finally,a lumped-mass train mode coupled with slab track is used to discover the relation -ship between vertical railway irregularity caused by subgrade settlement and train s dynamic responses when train passes by a railway location with certain type of subgrade settlement. Some design criterias for a reliable railway subgrade are proposed from the point view of train running quality.
Yunmin CHEN Xuecheng BIAN Hongguang JIANG Huanping SONG Zuozhou WANG
Department of Civil Engineering , MOE, Key Laboratory of Soft Soils and Geoenvironmental Engineering,Zhejiang University,Hangzhou 310058,China
国际会议
5th International Symposium on Environmental Vibration(第五届环境振动国际研讨会)
成都
英文
601-612
2011-10-20（万方平台首次上网日期，不代表论文的发表时间）