Analysis of stress redistribution in soil and earth pressure on tunnel lining using the discrete element method
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 6 m diameter tunnel buried at a 12 m depth with a gap of 4 cm 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 12 m and the tail gaps up to 8 cm result in a significant soil arching effect. The soil arching effect ceases to increase for buried depths of more than 12 m and for tail gaps of more than 8 cm.
Keywords: Earth pressure, Tunnel, Discrete element method, Principal stress inclination