Study on Protective Effect of Arched Double Row Piles on Existing Tunnel

Isolated piles are often used to protect existing tunnels at the edge of foundation pits in engineering practices. Currently, traditional rectangular pile layouts are mostly adopted in the arrangement of isolated piles. For the excavation of a building basement in Hangzhou, the arch double row isolated pile, which is composed of straight row piles and curved row piles, and the corresponding optimization scheme were proposed. A three-dimensional model was established by using the finite element software ABAQUS, and the influence of center distance, pile radius,plane position, and radius curvature of pile on the isolation effect was studied, together with a comparison with measured results. The results show that there is a maximum and minimum value of the total displacement of tunnel lining; the maximum total displacement of tunnel lining is located at the arch bottom, the minimum value occurs at the arch top, and the lining of the tunnel shows a general trend of subsidence. A reduction of the center distance a