Stability analysis of jointed rock mass in large underground caverns based on multi-scale analysis method

• Published in: Transportation Geotechnics 2023-09, Vol.42, p.101109, Article 101109
• Main Authors: Zhuang, Duanyang, Ning, Zexu, Argilaga, Albert, Ma, Ke, Tang, Chunan, Li, Jinlong, Xu, Wenjie, Zhang, Shuai
• Format: Article
• Language: English
• Subjects: Heterogeneity; Jointed rock mass; Multi-scale analysis; Scale effect; Stability
• ISSN: 2214-3912; 2214-3912
• DOI: 10.1016/j.trgeo.2023.101109

•A multi-scale equivalent analysis method for the stability of jointed rock mass is proposed.•Jointed rock mass is prone to macroscopic shear failure resulting from the aggregation and extension of tensile microcracks.•The mesoscopic rock heterogeneity and macroscopic random joints are described integratedly.•The plastic zone forms near cavern vault and bottom subjected to horizontal geo-stress. Random defects at different scales are the crucial cause of damage evolution and cascade transfer in rocks. For a large-scale underground cavern, the rock mesoscopic heterogeneity and macroscopic random joints are inevitable factors of rock stability, which needs to be further studied. In this study, a multi-scale analysis method for the stability of jointed rock mass in large underground caverns is proposed. The statistical damage theory is used to describe the mesoscopic heterogeneous rock damage. Monte Carlo simulation and measured joint geometric information are combined to reconstruct the macroscopic random joint network of rock mass. The integrated analysis of mesoscopic heterogeneity of rock and the macroscopic response of random jointed rock mass is performed by Rock Failure Process Analysis (RFPA) system. The research shows that the existence of joint affects the failure mode of rock mass and strengthens the heterogeneity. The representative elementary volume (REV) of jointed rock mass and its equivalent mechanical parameters are determined and used in the stability analysis of a large-scale underground cavern project. Results show a good agreement with the in-situ monitoring deformation of surrounding rock mass, which verifies the effectiveness of the rock mass multi-scale analysis method.