Analysis on the Influence of Cross Tunnel Construction on the Deformation of the Existing High-Speed Railway Tunnel

In order to study the influence of different spacing and angles of the axes of the two tunnels on the deformation and operation safety of existing tunnel in near-tunnel construction, the project in Fuzhou is taken to analysis. We use the finite element analysis software to construct a three-dimensional finite element model and carry on the numerical simulation, obtaining vertical vault displacement curves under different spacing and angles of the axes of the two tunnels. Then, we compare it with the actual monitoring data and do further analysis, we get following conclusions: (1) the main performance of the existing tunnel deformation is upward, the deformation decreases with the increase of the spacing and crossing angle, and the effect of the spacing on the existing tunnel vault deformation is far greater than the crossing angle. (2) When the spacing is less than 1.5 times of the new tunnel hole diameter, the maximum tunnel vault deformation occurs in the tunnel cross surface; when the spacing is greater than 1.5 times of the new tunnel hole diameter, the maximum tunnel vault deformation gradually moves toward to the center of the existing tunnel. The research results can provide some references for the design and construction of similar projects.