Experimental and Numerical Studies of a Shield Twin Tunnel Undercrossing the Existing High-Speed Railway Tunnel

In order to study the influence of shield tunneling on existing high-speed railway lines. Combined with centrifuge test and three-dimensional numerical simulation, the dynamic response of shield tunnel undercrossing existing high-speed railway tunnel was studied, and the influence of settlement joint and steel pipe pile reinforcement on existing tunnel was analyzed. The results show that: (1) the construction joints of existing tunnels significantly reduce the shielding effect of existing high-speed railway tunnels on the ground; (2) The settlement value of the existing tunnel caused by double-line shield tunnel construction needs to be controlled by steel pipe pile reinforcement to meet the requirements of the specification; (3) The double-line shield tunnel construction has little effect on the internal force of the existing high-speed railway tunnel, and the reinforcement of the high-speed railway tunnel lining meets the stress requirements.