Study On The Track Deformation And Dynamic Response Under The Conditions Of Shield Tunnel Down-traversing The Railway Transition Section

With the large-scale construction of urban rail transit, it will inevitably lead to the cross of some rail lines and crossing problems between node stations and section tunnels. As the weak link of rail lines, the deformation of road-bridge transition section will certainly effect the operation and safety of the whole line. In this paper, it has taken the down-traversing of shield tunnel under road-bridge transition section as an example which has been used the ABAQUS finite element analysis software to build the model of down-traversing of shield tunnel under railway transition section and the Vertical vehicle-track coupling model, and analyzed the influence of railway track geometry and dynamic characteristics by tunnel excavation. The main research findings are as following:(1) Through the simulation of the excavation process, the basic rules of track structure deformation in the excavation process have been found and some reasonable suggestions have been proposed.(2) Basing on the last achievements, and through building the Vertical vehicle-track unified model, the change rules of railway dynamic characteristics of road-bridge transition section and vehicle driving properties have been found by comparing three situations of track regularity, out and in bridge in the process of tunnel excavation.