Objective Driven by “dual carbon” goals, underground artificially lined gas storage caverns for compressed air energy storage (CAES) endure ultra-high internal pressure and frequent start-stop cycles under complex geological conditions. Over time, high pressure and cyclic loading can lead to damage propagation in surrounding rock and cracking in the lining, resulting in load redistribution and reduced gas tightness. Traditional continuum-based methods struggle to simultaneously model discontinuous crack evolution and the structural interaction of multi-layer systems. To address this, a structural analysis method based on the cohesive zone model (CZM) is proposed, clarifying the collaborative stress-bearing mechanism of the ternary sealing system comprising surrounding rock, concrete lining, and corrugated steel lining.

Methods Based on a hundred-megawatt-level project in Northwest China, a coupled finite-discrete element model incorporating surrounding rock, primary support, secondary lining, corrugated steel lining, and rubber cushion layer was established. Cohesive elements were embedded in the secondary lining to simulate crack initiation, propagation, and penetration. Numerical uniaxial compression and tensile tests were conducted to back-calculate and calibrate parameters such as fracture energy, peak traction, and interface stiffness. Full-process numerical calculations were performed under conditions including excavation, pressure increase to 10 MPa, and short-term daily regulation cycles.

Results Under maximum internal pressure, the deformation of the surrounding rock transitioned from sidewall convergence during excavation to overall outward expansion at the bottom, with displacement ranging from −8.62 mm to 9.15 mm. The plastic damage depth increased from approximately 1.20 m to 3.16 m due to irreversible accumulation. Cracking in the secondary lining was initiated at around 4.1 MPa, and a fully penetrated multi-stage secondary tensile-shear composite crack network formed at 10 MPa. The equivalent stress in reinforcement at the cracks rose sharply, exceeding 400 MPa and reaching the yield state, with more severe conditions observed in the inner ring. The corrugated steel lining remained elastic overall, experiencing a cyclic stress amplitude of approximately 150 MPa, which was below the allowable limit. During short-term cycles, crack propagation was most pronounced in the first cycle, with a maximum crack width of 1.09 mm, while the propagation rate significantly decreased and stabilized after three cycles.

Conclusion The proposed method can simultaneously characterize surrounding rock damage, discontinuous lining cracking, and mechanical evolution of sealing layers, providing a basis for optimizing crack-limiting reinforcement design, verifying sealing layer fatigue resistance, and assessing operational safety. In engineering practice, focus is recommended on controlling cracks near the invert and drainage structures, strengthening inner-ring reinforcement, and reducing crack-induced stress amplitude fluctuations to enhance long-term gas-tightness safety margins. Restricted by computational cost, temperature effects, reinforcement bond-slip behavior, and long-term full-cycle performance were not considered. Further multi-field coupling analyses and long-term operational validations are required in future research.