Numerical Simulation of Tunneling-Induced Stress and Deformation in Jointed Rock.

Tunneling in jointed or fractured rock masses presents a significant challenge due to the complex interaction between the excavation process and the pre-existing discontinuities. The presence of joints, faults, and bedding planes critically influences the stress redistribution, deformation, and overall stability of the tunnel. Traditional analytical and empirical methods often fail to accurately capture these intricate behaviors, necessitating the use of advanced numerical techniques. This research employs a finite-distinct element method (FDEM) to simulate the excavation of a circular tunnel in a representative joint rock mass. The model is built to replicate the in-situ stress conditions and incorporates a comprehensive constitutive model for both the intact rock and the joint network. The numerical results provide detailed insights into the evolution of stress concentration zones, the magnitude and distribution of rock mass deformation, and the mechanisms of joint slip and dilation. The findings demonstrate that discontinuities act as zones of weakness, leading to asymmetric stress redistribution and localized deformation. The study concludes that numerical simulation is a robust and indispensable tool for understanding and predicting the complex geomechanical response of jointed rock to tunneling, offering a superior alternative to simplified approaches for critical design and safety assessments.