3D GPU-accelerated FDEM for fracturing and stability analysis of jointed rock masses due to tunnel excavation

Abstract

The fracturing and instability of jointed rock masses during tunnel excavation is a complex process involving crack initiation, propagation, and intersection, as well as block spalling, overturning, and extrusion, which poses significant challenges to traditional continuous or discontinuous methods. Leveraging the hybrid Finite-Discrete Element Method (FDEM) and CUDA C/C++ programming model, this study develops a Ytunnel module within the 3D GPU-accelerated FDEM framework. The Ytunnel module incorporates approaches for in-situ stress generation, quasi-static excavation, and detailed rock joint characterization. The effectiveness of the developed method is first validated through two numerical examples: a homogeneous stratum excavation, which demonstrates close alignment with theoretical predictions of stress evolution, and a simulation of the classic URL test tunnel, which accurately captures field-observed damage zone. The failure process of surrounding rock in jointed rock masses caused by tunnel excavation is also investigated. The results reveal that the presence of joints plays a critical role in the fracturing and instability of surrounding rock. The 3D GPU-accelerated FDEM integrated with the Ytunnel module offers a powerful and versatile approach for investigating the complex behaviors of rock masses induced by tunnel excavation.