Study on the Stability of Rock Walls in Shallow-Buried Tunnels with Small Clearances in Layered Rock Masses

Abstract

AbstractIn the engineering of tunnels with small clearances, the structural features of rock layers play a crucial role in the stability of the central rock walls. This study employed the Discrete Element Method software (UDEC) to simulate the mechanical response of tunnels with small clearances under various rock layer dip angles, both in unfortified conditions and when reinforced with shotcrete. The research thoroughly examined the deformation patterns of the central rock walls, the development process of the plastic zones, and the dynamic changes in the stress distribution along the rock layer interfaces. The findings indicate that the deformation of the central rock walls is most significant when the rock layer dip angle is around 60°. Timely reinforcement with shotcrete effectively restricts the expansion of the plastic zones. Additionally, the characteristics of the rock layer interfaces play a decisive role in the stability of the central rock walls, with a higher risk of slip failure under certain dip angles.