Modeling the Effects of Internal Erosion on the Structural Damage of a Shield Tunnel

摘要

This study investigated the soil-structure interaction and structural damage of a shield tunnel during construction caused by the internal erosion of the sandy ground. A numerical approach was proposed to qualitatively simulate the erosion process and was validated by the results of triaxial erosion tests from the literature. The concrete linings and bolts were modeled using elastoplastic models. The mechanisms of structural damages induced by internal erosion at different locations were identified. It was found that the main structural damage was the yielding of joint bolts caused by segmental joint displacements, which in turn were the results of the associated soil-structure interaction induced by the decrease of soil strength and stiffness during internal erosion. A parametric study was conducted to investigate the effects of the extension and the parameters of internal erosion.