Analysis of Existing Railway's Subgrade Settlement Caused by Excavation Pit

With the increase of high-speed train's speed, the dynamic response of track structure will be increased,which require more about the track geometry. This paper takes the excavation pit on Hu-Ning intercity passenger rail by the side of existing railway line for example to analyze dynamic response of subgrade caused by the excavation pit. In order to analyze the subsidence of subgrade caused by the excavation of foundation ditch,the numerical model was set up,which is composed of two parts, including the train-track-subgrade coupled system and the subgrade-ground-foundation ditch coupled system. The results show that the vertical dynamic displacement in six representative conditions are between 0. 8 to 1. 6 mm, and the depth, the support method and the dynamic loads will induce the different sedimentation of the subgrade.