Physical Model Test on Damage Evolution of Surrounding Rock-Lining Structure in Abandoned Mine Compressed Air Energy Storage Caverns under Cyclic Loading

Abstract

To clarify the damage evolution characteristics of the surrounding rock-lining structure under cyclic loading, a physical model testing method was adopted, focusing on the gas storage space of lined chambers in hard rock roadways in abandoned mines. A large-scale three-dimensional simulation model test system for the surrounding rock-lining structure of compressed air energy storage tunnels was developed. Conductive concrete was used as the analogous material. A multi-source monitoring system was established, including dynamic and static strain acquisition, distributed optical fibre sensing, and networked parallel electrical testing. The stress, deformation, and resistivity fields of the surrounding rock-lining structure were synchronously monitored. The results indicate that:

(1) Under the combined effects of boundary stress and excavation unloading, the vertical stress at the roof and floor of the lining and the horizontal stress at the sidewalls are progressively released from shallow to deep regions along the measurement lines. In contrast, the horizontal stress at the roof and floor and the vertical stress at the sidewalls increase synchronously, resulting in stress concentrations in the roof region and the deeper parts of the sidewalls.

(2) Under both single-stage and graded cyclic loading, the structural stress exhibits periodic fluctuations, with the response amplitude increasing as the upper limit stress rises. The regions adjacent to the lining show the most significant variations.

(3) During the excavation stage and under single-stage internal pressure, the structure is primarily characterised by compressive deformation, with more pronounced compression at the sidewalls than at the roof and floor. As the upper limit stress of graded cyclic loading increases, the deformation gradually transitions from compression to tension. When the stress exceeds 1.0 MPa, the peak tensile strain at the roof and floor reaches 700-1000 με, accompanied by significant non-uniform deformation.

(4) Apparent resistivity results demonstrate that, with increasing upper-limit stress, microcracks within the lining progressively propagate, leading to the formation of high-resistivity damage zones in the roof, floor, and shallow sidewall regions. These changes effectively reflect the damage evolution process of the structure. The findings provide a basis for understanding the macroscopic stress redistribution, deformation behaviour, and failure mechanisms of surrounding rock-lining systems in gas storage roadways of compressed air energy storage power stations under cyclic loading.