Numerical Investigation of Ground Settlements Induced by the Construction of Nanjing WeiSanLu Tunnel and Parametric Analysis

Tunnel lining stiffness, grout strength and shield-driven speed are important parameters that influence ground surface settlement during tunnel excavation. Optimising these parameters would allow effective control of ground settlement during tunnel construction, specifically the maximum settlement. This paper investigated the influence of tunnel lining stiffness, grout strength and shield-driven speed on ground settlement in heterogeneous soil. Consequently, a 3D nonlinear finite element model was developed using Abaqus which accurately predicted the ground settlement during the construction of the Nanjing WeiSanLu tunnel. Furthermore, the influence of the shield-driven speed, modulus of elasticity of grout and tunnel lining stiffness on ground surface settlement was studied. Statistical analysis was performed to investigate the level of impact of each influencing factor and their two-way interaction on the maximum ground settlement. It was revealed that ground surface settlement is greatly influenced by the properties of tail voids grouting and stiffness of tunnel lining. The result also indicated that the relationship between the prediction factor and the maximum settlement on the ground differs according to the level of the studied factors.