Numerical Analysis of Ground Displacement and Pile Response Due to Tunneling in Soft Soil Considering the Creep Behavior

Abstract

The additional pile response due to the creep behavior of the soil is disadvantageous to the safety of pile. However, in the current studies for considering the creep behavior of the soft soil, the pile response induced by the long-term settlement of soil is seldom investigated. This paper mainly discusses the pile response during the excavation and operation periods considering the creep behavior of soft soil. The finite difference software FLAC3D is utilized to simulate the excavation of tunnel and the creep behavior of soil based on the two-stage analysis method. In the first stage, the displacement controlled method (DCM) is applied to simulate the instantaneous settlement of soil during excavation period. In the second stage, the creep behavior of soft soil is considered to estimate the long-term settlement of soil during operation period. While the creep behavior of soil is not considered, the simulation results such as the shape of trough, pile response are compared with the results of existing studies, and the numerical model is verified to be acceptable. While the creep behavior of soil is considered during the operation period, the influence of the creep behavior on the pile response such as its deflection, settlement, axial force and bending moment of the long-term soil settlement are discussed. The effects of the four typical mechanical parameters in the creep model on soil deformation and pile response are investigated.