Impact Analysis on Existing High-speed Railway Tunnel by the Construction of New Tunnel-Overpass

In order to study the influence of the deformation and stress of the existing tunnel structure under different distance and cross angles, the actual project in Fuzhou city was taken to analyze. The finite element analysis software was used to construct the three-dimensional finite element model for numerical calculation, and obtained a variation curves of vertical displacement and stress at different distances and angles. Numerical results show that: (1) When the distance is 1.5 times less than the diameter of the new tunnel, the maximum vertical deformation of the existing tunnel occurs at the intersection of the two tunnels. When the distance is 1.5 times more than the diameter of the new tunnel, the maximum deformation of the existing tunnel is gradually moving toward the center of the existing tunnel. (2) The influence of the first principal stress and the deformation of the existing tunnel is mainly affected by the distance, and the cross angle has little effect. May the research results can provide some reference for the design and construction of similar projects.