Objective Compressed air energy storage (CAES) power plants, which realize the cyclic conversion between electrical energy and internal energy of air, are considered a promising new technology for energy storage and power generation. However, the sealing performance of underground caverns significantly restricts energy storage efficiency, and there is a complex contact force transfer relationship between the sealing steel lining and the concrete lining. Therefore, this paper aims to analyze the stress damage evolution of the steel lining and concrete lining under high pressure, propose reasonable design parameters for the steel lining thickness, and investigate the lining cracking patterns to ensure the safety and stability of the cavern during operation.

Method Based on a planned underground CAES cavern, a three-dimensional global numerical model of the surrounding rock-concrete lining-steel lining was established. A plastic-damage model considering concrete softening characteristics was adopted, and surface-to-surface contact elements with a Coulomb friction model were introduced between the steel lining and the concrete lining. The effects of friction coefficient, steel lining thickness, air storage pressure, and concrete cracks on the stress damage evolution of the structure were systematically analyzed.

Result The results show that an increase in the friction coefficient μ aggravates the tensile damage at the waist of the concrete lining, and the effect tends to stabilize when μ ≥ 0.6. Increasing the thickness of the steel lining has little influence on reducing the hoop stress in the concrete lining and cannot effectively inhibit lining cracking. The hoop stress at the lining waist increases linearly with the rise of air storage pressure, and the compressive damage is more sensitive than the tensile damage. As the width of the concrete crack increases, the maximum principal stress in the steel lining at the crack location shows an increasing trend. The concrete lining can work with cracks, but the influence of crack width on the sealing layer needs to be assessed to guarantee operational safety.

Conclusion The contact force transfer behavior between the steel lining and the concrete lining should be properly considered in the design of the sealing steel lining thickness.