A Study of Stability and Pericavity Strain in an Underground Cavern Group for Compressed Air Energy Storage

The stability of underground caverns for compressed air energy storage (CAES) is critical for safe operation under high internal pressure conditions. With the development of large-scale CAES power plants, a single storage cavern can no longer meet energy storage demands, making the study of cooperative stability in cavern groups of significant engineering importance. Based on a three-dimensional numerical simulation method, this study establishes a cavern group model to systematically investigate the influence of burial depth, cavern diameter, and spacing on surrounding rock deformation and plastic zone distribution, with a particular focus on the stability of intersecting regions. The results indicate that: (1) Surrounding rock deformation decreases with increasing burial depth but exhibits an upward trend with larger cavern diameters. When the spacing exceeds 1.5D, the deformation gradually stabilizes. (2) Under an operating pressure of 15 MPa, the optimal layout parameters for the cavern group are a burial depth of 200 m, a cavern diameter of 5 m, and a spacing of 1.5D. (3) Displacement in intersecting regions is generally higher than in single-cavern sections, particularly at the connection between vertical shafts and main caverns, where deformation shows asymmetry, with greater displacement on the side adjacent to neighboring caverns, indicating significant interaction effects within the cavern group. This study provides a theoretical basis for the optimal design of underground CAES cavern groups under high internal pressure conditions. Article type: Research article Cited as: Han ZC, Fan MM, Xu DB, et al. 2025. A Study of Stability and Pericavity Strain in an Underground Cavern Group for Compressed Air Energy Storage. GeoStorage, 1(1), 56-70. https://doi.org/10.46690/gs.2025.01.04