Numerical Simulation of Mechanical Response of Bridge Foundation and Existing Tunnel Caused by Pipe Jacking Construction

Upward ( phase i ) pipe jacking project of hangzhou water intake is near existing bridge foundation and operating tunnel. In order to investigate the influence of pipe jacking construction process on existing structures, Plaxis 2D finite element software was used to simulate the horizontal and vertical displacement of existing structures caused by pipe jacking construction. The calculation results show that: The horizontal displacement of bridge pile foundation is nonlinear distribution. There is a bending point in the pile foundation. The maximum and minimum horizontal displacement are 0.71 mm and-0.84 mm, respectively. The maximum vertical settlement is only 0.29 mm. The horizontal displacement of the sidewall of the tunnel structure is nonlinear distributed, and the displacement near the pipe jacking is relatively large, but the maximum displacement is only 0.13 mm. The vertical deformation of tunnel structure is mainly uplift deformation, and the uplift near the pipe jacking is obvious, but the extreme value of uplift is only 0.09 mm. Thus, the impact of pipe jacking construction on bridges and tunnels is very limited. The research results are of great significance to the safety evaluation of pipe jacking engineering near construction.