Inner pressures of lined rock caverns for compressed air energy storage using Hoek-Brown criterion

The cyclic charging and discharging in compressed air energy storage (CAES) lined rock caverns (LRCs) often induce a plastic state in the surrounding rock, resulting in cumulative plastic damage that shortens the facility's lifespan. To ensure long-term stability, it is crucial to define the allowable operating pressure by determining the minimum and maximum inner pressures that keep the surrounding rock within the elastic regime, based on elastic theory. To address this issue, an analytical solution for determining the minimum and maximum inner pressures in LRCs using the Hoek-Brown criterion is presented. The solution elucidates the physical significance of operating pressure in LRCs and demonstrates that appropriate scaling of the Hoek-Brown parameters significantly simplifies its determination. The effectiveness of the proposed analytical solution is validated through comparisons with both the binary search method and numerical simulations. A parametric sensitivity analysis considering crustal stress p b , lateral stress coefficient λ , geological strength index GSI, material constant m i , uniaxial compressive strength of intact rock (UCS) σ ci and disturbance factor D is carried out. The analysis reveals that the maximum inner pressure is primarily influenced by the lateral stress coefficient, crustal stress, and GSI, while GSI has a large effect on the minimum inner pressure. In addition, a series of charts detailing the recommended operating pressure ranges for high-frequency cyclic operation in LRCs is provided to facilitate the rapid preliminary assessment of operating pressure during the design phase.