Abstract: Reinforced concrete liner serves as a critical component in the structural integrity of artificially excavated underground gas storage caverns. Its cracking and deformation characteristics in response to the high internal gas pressure significantly affect the design and operational performance of the cavern’s sealing structure. This study adopts a fixed crack model for concrete simulations to evaluate the design of the reinforced concrete liner for a JQ high-pressure gas storage cavern in Gansu province. We first validate it against a four-point bending beam tests in literature, then conduct a series of numerical simulations of the non-linear fractures in the cavern liner, focusing on the progressive development of multiple cracks and their opening widths in response to gradually increase of gas pressure in the cavern. An analysis is also made on the effect of omitting the reinforcing measure and the effect of accounting for the hysteresis effect of concrete cracking on the liner￠s fracture response during the fluctuating cycles of internal pressure. The results show that the liner’s progressive cracking is characterized by a multi-crack distribution, predominantly distributed radially and extending through the entire liner thickness. Based on the design parameters for concrete and reinforcement, we attain the liner’s maximum crack opening controlled below 1 mm under an internal pressure of 18 MPa, and demonstrated the cycling of pressurization and depressurization in the cavern does not significantly deteriorate the crack opening in a reinforced concrete liner. The results deepen the understanding of liner cracking for the design of support structures and sealing layers of gas storage caverns, and help predict cavern liner cracking for service performance.

Key words: compressed air energy storage, artificial gas storage cavern, high internal pressure, reinforced concrete, hysteresis effect