Analysis of stress redistribution in soil and earth pressure on tunnel lining using the discrete element method

Abstract

This paper analyzes the stress redistribution in the surrounding soil and the earth pressure acting on the shield tunnel lining due to tunneling. The construction of a 6m diameter tunnel buried at a 12m depth with a gap of 4cm with the surrounding soil is modeled using DEM, utilizing the equivalent mass method. The principal stresses and their inclination angle in the surrounding soil are examined together with the earth pressure acting on the tunnel lining. Soil arching and unloading effects due to tunneling are also investigated. Furthermore, the construction of the tunnel at different buried depths and with different tail gaps is modeled. All the comparisons show that increasing the buried depth up to 12m and the tail gaps up to 8cm result in a significant soil arching effect. The soil arching effect ceases to increase for buried depths of more than 12m and for tail gaps of more than 8cm.