An Analytical Solution for Ultimate Air Pressure in a Subsea Rock Cavern for Compressed Air Energy Storage Based on Uplift Limit Analysis

ABSTRACT A calculation method for the ultimate internal air pressure is urgently needed for the design of a planned Subsea Compressed Air Energy Storage (SCAES) cavern in the coastal area of Fuzhou, China. Unlike the existing methods, the calculation requires comprehensive consideration of the coupled effects including internal pressure, pore pressure and seawater burial depth. Therefore, this study proposes an analytical solution for the ultimate internal air pressure of SCAES caverns based on Hoek–Brown criterion. The proposed approach also utilizes the virtual work principle and limit analysis as the theoretical bases. The accuracy and feasibility of the proposed analytical solution are verified by comparison with other analytical methods for CAES when the influence of water and seawater depth is ignored. The proposed approach is also applied to a planned project for a case study. The results show that increasing parameter and parameter reduces failure surface slope while enhancing critical pressure. Enhanced permeability marginally affects the failure surface geometry and significantly increases uplift trend. The increase in the parameter as a power‐law term leads to a nonlinear reduction of internal pressure. The ultimate internal pressure escalates rapidly beyond a crack initiation angle of 70. Water–soil depth increases both failure surface slope and critical pressure. This study provides critical references for site selection and engineering design of SCAES.