Three-Dimensional Numerical Simulation of Soil Deformation during Shield Tunnel Construction

Abstract

In order to effectively control the ground deformation and ground subsidence during subway construction, three-dimensional numerical simulation of soil deformation during shield tunnel construction is proposed. Based on a subway tunnel project, this essay firstly divides the shield construction process into several stages and analyzes the vertical displacement of soil in each stage. FLAC 3D was used for three-dimensional finite difference numerical simulation. By comparing the numerical simulation results with the field measured data, the soil settlement caused by shield tunnel excavation is studied deeply. The simulation results show that the maximum settlement value of the monitoring data is 0.59 mm, and the maximum settlement value of the numerical simulation is 0.82 mm, with a difference of 0.23 mm. The maximum value of uplift on both sides of the tunnel is 0.41 mm in monitoring data and 0.29 in numerical simulation, with a difference of 0.12 mm. The maximum settlement value of monitoring data is 2.59 mm, and the maximum settlement value of numerical simulation is 3.05 mm, with a difference of 0.46 mm. The maximum value of uplift on both sides of the tunnel is 0.32 mm in monitoring data and 1.89 mm in numerical simulation, with a difference of 1.57 mm. The settlement value of numerical simulation is slightly larger than that of monitoring data. Conclusion. The simulation can well simulate the state of soil uplift on both sides, and the width of settlement groove is in good agreement with the monitoring data.

Analysis of Surface Settlement Induced by Shield Tunnelling: Grey Relational Analysis and Numerical Simulation Study on Critical Construction Parameters

“…The shield tunnelling method has become the primary construction method for underground metro projects, owing to the rapid construction speed, automated operation, and minimal impact on surface traffic. However, shield tunnelling inevitably disturbs the surrounding rocks, leading to stress redistribution within the soil [1] and inducing surface settlement [2,3]. The excessive surface settlement can damage adjacent buildings and infrastructure [4,5], jeopardizing the safety of pedestrians, vehicles, and roads [6].…”

Liquid-Solid Coupling Response of Surrounding Rock Mass of Large-Diameter River-Crossing Shield Tunnel

“…In addition, numerical analysis is a favorite method for studying ground deformation caused by shield tunneling. Liu et al [15] established a threedimensional finite difference numerical model employing FLAC 3D, considering the factors such as trapezoidal support force, shield cone, trapezoidal grouting pressure, grouting body solidification, timely placement of lining, the soil settlement caused by shield tunnel excavation in silty sand stratum was studied. Using the discrete element method, Hu et al [16] studied the surface and underground deformation characteristics of sandy soil under various burial depths and screw conveyor speeds.…”