Analysis of the Influence of Deep Foundation Pit Excavation with Diaphragm Wall Support on Deformation of Adjacent Metro Tunnels

On the north side of a deep foundation pit in Nanjing, the diaphragm wall support is located at a minimum net distance of only 12 m from an operational metro tunnel. To control the deformation of the metro tunnel, triaxial cement-soil mixing piles were adopted for slot wall reinforcement on both sides of the diaphragm wall. Based on this project, the MAIDAS/GTS finite element software was used to conduct 3D numerical simulations of the longitudinal and transverse displacements of the adjacent metro tunnel caused by deep excavation under diaphragm wall support. The effectiveness of the cement-soil mixing pile reinforcement measures was analyzed and compared through simulation calculations, aiming to provide references for similar designs and constructions.