The Analysis Of Track Deformation Law And Dynamic Response When The South-to-North Water Diversion Tunnel Down-traversing The Tram

Due to its wide applicability and construction flexibility,modern trams have become an important way to solve the traffic problems in small and medium-sized cities,and have been widely used in China.As the length and density of tram lines continue to increase,new underground projects inevitably cross the existing track lines.Various types of crossing projects are increasing.Since the shield tunneling method is mainly used in the construction of new underground projects in the city,it is of great significance to predict the impact of the shield tunneling on the existing tramway construction before the work,which is important for ensuring the existing line structure and train operation safety.At present,there are few studies on shield tunnels crossing tram lines.Because the vehicle parameters and track structure of trams are unique compared with traditional subways and light rails,it is of great practical significance to conduct research on shield tunneling through tram lines.Based on the project example of the western suburb of the tram line under the water diversion tunnel of Beijing south-to-north water transfer project,the paper studies the deformation law and dynamic response of the track structure of the tram line.The main work is as follows:1.Based on the project case of crossing the Xijiao line,according to the location relationship between the new project and the existing line,the static simulation model is established for the parallel section and the down-traversing section respectively with the finite element software ANSYS.This paper studies the deformation law of track structure of existing tram lines under different position relations,and provides reasonable Suggestions for the control index of new construction based on the predicted results.2.The actual monitoring data of the Xijiao line project and the numerical simulation results are compared and analyzed.The reliability of the data obtained by the numerical simulation method is verified by comparing the vertical deformation limit values and deformation trends of the existing track bed and rail of multiple construction nodes.3.Based on the deformation curve obtained by the static model,the vehicle-track coupling dynamics model was established by ABAQUS finite element software.The train and track dynamic characteristics evaluation indexes were compared under different vehicle speeds,before and after the engineering track deformation and under different track structures.Predict and evaluate the safety of tram operation and track structure and propose the allowable value of the track structure deformation limit.In order to provide reasonable suggestions for ensuring the safety of the line during construction,the technical reference for the selection of rails for new tram lines is provided.Figure 118,table 26,reference 73.