Analysis for dynamic load behavior of shield thrust system considering variable boundary constraints

Abstract

In this paper, the load transmission model of the shield thrust system is established taking into account the variable boundary constraints between the shield skin and the surrounding strata, which is obtained based on the finite element methods. The results show that the resisting moment on the shield skin from the geologic layer has a nonlinear relationship with the bending moment loads on the cutterhead when the material behavior of the strata is modeled by an elasto-plastic Mohr-Coulomb model. The dynamic load behavior of the shield thrust system is significantly influenced by the variable shield-strata boundary constraints, which may cause incorrect load predictions of the hydraulic thrust system and consequent snake-like motions of the shield machine. © 2009 Springer-Verlag Berlin Heidelberg.