Support and reinforcement design with stability analysis of rock mass for underground caverns of a pumped storage power station

ABSTRACT: The stability of surrounding rock and the effectiveness of anchorage support are critical factors in designing and constructing underground powerhouse caverns in hydropower stations. Using the Lingshou Pumped Storage Power Station as a case study, we employ three-dimensional finite difference software FLAC3D to perform numerical simulations for support design and stability analysis. Our results validate the feasibility of the Q-system and Basic Quality classification for support design, confirming their applicability in underground engineering projects. Through secondary development in FLAC3D, we modify the Cable elements to simulate tensile failure of rock bolts, improving the accuracy of bolt behavior representation. This modification enables a more realistic assessment of anchorage performance under complex stress conditions. Based on these findings, we conduct a comprehensive analysis of anchor support effectiveness and cavern complex stability.