Abstract:

Tunnel construction with underground excavated method in soft soil often induces ground deformation. Due to that the city underground excavation tunnel lies in area with dense and intensive buildings, the damage of soil deformation to adjacent structure is noticeable. 2D FEM is adopted to study and simulate the underground excavated tunnel construction of adjacent structure. The building is with length of 15m. It is indicated as follows. Surface settlement together with force and deformation of the lining are increased by the existence of building; simultaneously, additional stress and deformation of adjacent structure are induced during tunnel excavation construction. L is defined as horizontal distance from tunnel axis to building axis. When 0 m, the building is relative secure. When , the building incline to sides of tunnel. When to 20 m, great surface settlement is produced with more settlement difference between building head and tail; and the building is in danger. When to 40 m, the impact of building on the tunnel construction is small. When 40 m, the influence of building on the tunnel construction is negligible. As a result of the foundation, the maximum of bending moment, the axial force and the shearing force vary little; with extends range is less than 10 %.

Key words: underground excavated tunnel, structure, numerical simulation, surface settlement