Under the rigid foundation conditions of bridge and tunnel sections,ballasted tracks are more prone to deterioration.Therefore,elastic ballast pads are usually laid to improve the stress state of ballasted tracks.This article used the discrete element method to establish a simulation model of the ballasted track bed of high speed railways,and analyzed the differences in dynamic stiffness of the track bed,indirect contact force between ballast particles,and contact force between the bottom ballast of the track bed and the foundation under different working conditions under rigid foundation.The results show that after the width of the ballast pad exceeds the length of the rail sleeper,the incremental improvement effect brought by increasing the laying width of the ballast pad will gradually decrease.The double block laying form will cause stress concentration in the middle of the rail sleeper,resulting in increased contact force of the ballast and the adverse effect of rail sleeper caused by the negative bending moment at the mid span.For ballasted track structures with rigid lower foundation conditions such as high speed railway bridge and tunnel areas,it is recommended that ballast pads should be laid with a width of 2 600 mm,which is equal to the width of the sleepers,and the centerline should coincide with the centerline of the sleepers.
关键词
高速铁路/有砟道床/离散元/道砟垫/铺设宽度
Key words
high speed railway/ballasted bed/discrete element/ballast pad/laying width
维普
万方数据