Analysis Of Differential Settlement Of Subgrade Effecting On Slab Track Dynamics

Differential settlement of subgrade have been the main restriction for expansion and utilization of the slab track.Differential settlement of subgrade lead to train running behavior decrease and effect passenger comfort, and also increase the part’s vibration of locomotive, then decrease their fatigue lifetime. Meanwhile, differential settlement of foundation soil makes the stress of track plate and bed plate increase rapidly, and induce the crack of the slab, consequently the track deterioration possibly happen. So study the train response to differential settlement of foundation, then limit the allowed reasonable amplitude; And study the stress distribution law of track plates and bed plates. So as to configure strengthen reinforcement reasonably, which has important significance for the popularization and application of slab track on the subgrade.This paper adopts ANSYS finite element software to simulate the train running state of differential settlement section. Apply vehicle-track vertical coupling model, and by the combined application of the shell element and beam element and spring-damper element carring on transient analysis. And analysis the relationship of vertical vibration, wheel-rail force as well as the vertical stress of track slab and the train speed, the chord length of the differential settlement of subgrade as well as the amplitude of the differential settlement of subgrade. Then basised on the passengers’ riding comfort, the limit values of the differential settlement is given which corresponding to different speed and different chord.Also, this paper used solid model and quasi-static load to simulated the working state of track structure in the section of the differential settlement of subgrade. And find the transverse and longitudinal stresses distribution law of track plates and bed plates. The author compared the working state between framed plates and A plates in the section of the differential settlement, andmakes a comparison of their adaptation to the section of differential settlement.