关键词: 压气储能, 内衬式地下洞室, 裂缝宽度, 预设缝衬砌

Abstract: The concrete lining of underground caverns used for compressed gas energy storage is prone to wide cracks under high internal pressure, which can exceed safety design values and affect the safety of the lining. To address this problem, it is usually necessary to reduce the cross-sectional size, increase the lining reinforcement ratio and reduce the gas storage pressure, which raises construction costs and limits storage capacity. This study adopts a preset crack lining structure that reduces tensile stress by releasing the circumferential displacement of the lining. This structure enhances the resistance of the surrounding rock to the lining, so that the surrounding rock can bear more loads and fully utilize its self-bearing capacity. Relying on actual projects, a two-dimensional numerical model was established with different preset crack depths, positions and numbers. The optimal design scheme for preset crack lining was proposed by analyzing lining damage factor and steel bar stress distribution. The results show that: to effectively release the lining stress, preset cracks must penetrate and sever steel bars. The preset crack lining structure significantly reduces the lining damage and steel bar stress, especially within the 15° range of the cracks. Symmetrical preset cracks prevent the overlap of influence ranges, which can increase far-end steel bar stress. Increasing the number of preset cracks can alleviate lining damage at the joint far ends. However, more preset cracks raise construction costs and complexity while reducing lining quality. Under design requirements, six through symmetrical preset cracks are optimal at a lateral pressure coefficient of 0.39, and four through symmetrical preset cracks are optimal at a lateral pressure coefficient of 1.5.

Key words: compressed air energy storage, lined underground cavern, crack width, preset crack lining