Simulation Analysis on Ground Surface Settlements and Creep Behavior Induced by Double-O-Tube Shield Tunneling

Abstract

This paper is a case study of Taipei-Sanchong section of Taoyuan International Airport access mass rapid transit system. This is the first project constructed by the Double-O-Tube (DOT) shield tunneling in Taiwan. The advancing of DOT shield tunneling induces ground settlements during construction, thus affecting the safety of buildings or facilities in neighboring areas. The finite element (FE) program—Plaxis2D—was used to simulate the process of DOT shield tunneling. Six monitoring sections along the alignment were adopted for the study in this paper. The Hardening Soil model with small-strain stiffness was selected to simulate the ground surface settlements and was compared with the former study performed by the Mohr-Coulomb model. For the sake of understanding the creep behavior during tunneling, another soil constitutive law—Soft Soil Creep model—was also adopted in the studies. Comparing the data of in-situ monitoring, the numerical analysis results could be conveniently and reliably used for the simulation of ground surface settlement. It is hoped that this case study will shed some light on future projects of a similar nature.