为解决高内压作用下压气储能地下硐室柔性密封层易发生陷缝破坏的工程难题，提出一种由丁基橡胶与碳纤维复合材料（carbon fiber reinforced polymer，CFRP）协同作用的复合柔性密封层新构造。该构造通过在密封层与衬砌之间引入CFRP，形成“柔性密封-高强度箍束”的协同工作体系。结合室内试验结果和实际工程案例，对安装复合柔性密封层的压气储能地下硐室进行加压模拟，系统研究复合柔性密封层在不同典型衬砌裂缝宽度（1、2、3 mm）下的抗陷缝破坏能力和协同变形机制。结果表明： 1）该新构造有效提升了复合柔性密封层的抗陷缝能力，在1、2、3 mm衬砌裂缝宽度下的最大承载压力较单层柔性密封层分别提升46.80%、75.10%、72.11%； 2）揭示了“柔性密封-高强度箍束”的协同工作机理，即CFRP的箍束作用有效抑制了丁基橡胶的径向变形，使其最大径向位移从3.19 mm降低至3.02 mm，降幅为5.33%； 3）在高内压工况下，CFRP虽承受较高环向拉应力但未超限破坏，且该结构的引入未改变衬砌与围岩的受力状态。
Flexible sealing layer of compressed air energy storage (CAES) caverns is prone to crack-induced extrusion failure under high internal pressure. To address this engineering challenge, a novel composite flexible sealing layer, combining butyl rubber with carbon fiber-reinforced polymer (CFRP) is proposed. By introducing CFRP between the sealing layer and the concrete lining, this structure forms a synergistic working system of “flexible sealing and high-strength confinement”. Pressurization simulations of the CAES cavern equipped with the composite flexible sealing layer were conducted based on laboratory test results and a real-world engineering project. The resistance to crack-induced extrusion failure and the synergistic deformation mechanism of the composite layer under various typical lining crack widths (1 mm, 2 mm, and 3 mm) were systematically investigated. The results indicate the following: (1) The composite structure effectively enhanced the anti-extrusion capacity of the flexible sealing layer; under these crack widths, the maximum bearing pressures were increased by 46.80%, 75.10%, and 72.14%, respectively, compared with the single flexible sealing layer. (2) The synergistic working mechanism of “flexible sealing and high-strength confinement” was revealed: the confinement effect of the CFRP effectively restrained the radial deformation of the rubber, reducing its maximum radial displacement from 3.19 mm to 3.02 mm, representing a decrease of 5.33%. (3) Under high internal pressure conditions, although the CFRP bore a high hoop tensile stress, it did not exceed its ultimate failure limit; moreover, the introduction of this structure did not alter the stress states of the concrete lining and the surrounding rock. The research findings elucidate the structural advantages of the composite flexible sealing layer, providing a novel scheme for the safe design of flexible sealing systems in underground CAES caverns under poor surrounding-rock geological conditions or excessively high internal pressure.
