Responses of the ground and adjacent pile to excavation of U-shaped tunnel

Abstract

Although there are many studies on the impact of tunnel on the surrounding environment, most of them focused on the circular tunnels but very few on U-shaped tunnels. In order to obtain a better understanding of the impact of U-shaped tunnel excavation on the ground and adjacent pile foundations, a simplified analytical method is developed in this work. The U-shaped tunnel is projected into a unit circle using conformal mapping method. The displacement and stress of the soil around the tunnel are solved analyzed. The settlement of a single pile is obtained by the complex variable function and the load transfer method. The influence of grouting is considered in the calculation. The analytical solution is verified by the simulation results given by an equivalent numerical model and validated with the field-measured data in an engineering case in Beijing.