Mechanical and deformation analysis of surrounding rock of compressed air caverns based on cyclic hardening model

Compressed air energy storage in underground caverns is a feasible solution for large-scale energy storage. In studying the mechanical and deformation characteristics of surrounding rock under long-term cyclic loading in compressed air caverns，traditional models mostly adopt elastoplastic models or statistical damage models based on the Mohr-Coulomb yield criterion. However，these models do not consider scenarios where the pressure inside the cavern falls below the fatigue threshold. To address this issue，the rationality of using a cyclic hardening model to calculate the deformation modulus and displacement of the surrounding rock in the case of the cavern pressure being below the fatigue threshold is demonstrated firstly. Then the cyclic hardening model is derived using axial residual strain as the internal variable. On this basis，the influence of fatigue parameters of different rock types on the mechanical and deformation characteristics of the surrounding rock of the compressed air chamber is studied. The model′s predicted values are compared with the measured values from on-site experiments，demonstrating its ability to accurately predict the deformation of the surrounding rock. © 2024 Academia Sinica. All rights reserved.