Stability analysis of underground cavern group regarding Yongxin pumped storage power station

This research presents an in-depth analysis of the stability of the surrounding rock of the underground powerhouse at the Yongxin Pumped Storage Power Station in Jiangxi. The study encompasses the rationality of the cavern layout spacing, the impact of excavation construction on surrounding rock stability, stability analysis of the surrounding rock under unsupported conditions, and stability analysis under-supported conditions. Using numerical simulations and on-site monitoring data, the deformation characteristics, stress distribution, plastic zone development, and the effectiveness of support measures during the excavation process of the underground cavern group were evaluated. Key data include the average deformation of the main powerhouse crown ranging from 11-41 mm, the sidewalls ranging from 30-88 mm, and the main transformer cavern crown ranging from 11-30 mm. The results indicate that systematic support measures can effectively reduce surrounding rock deformation, control the development of plastic zones, and alleviate stress concentrations, thereby enhancing the stability of the surrounding rock.