Author(s): Wang Qiyun, Zhang Jiasheng, Meng Fei
Pages: 17-20,21
Year: 2014 Issue:  10
Journal: Railway Standard Design
Keyword:  Ballastless track; Subgrade; Uneven settlement; Dynamic response; Distribution pattern;
Abstract: In order to analyze the influence of uneven settlement on the dynamic characteristics of ballastless track subgrade, a 3-D dynamic finite element model of CRTSII ballastless slab track subgrade is established, and the vertical dynamic stress, the dynamic displacement and the vibration acceleration of subgrade are calculated and analyzed under the conditions with and without defects. The results show that the dynamic response amplitude and spatial distribution of ballastless track subgrade are obviously changed in case of uneven settlement of subgrade, especially in subgrade 0 ~ 1. 5 m depth within the scope of bearing Layer. The dynamic stress induced by uneven settlement may reach 100kpa, which is more than 3 times of the subgrade without defect. Vertical acceleration also increases more than twice of that without defect. Results also show that the area of uneven settlement develops at a higher rate under repeated train load, which may bring great negative impact on subgrade.