Elastoplastic theoretical analysis of load-bearing mechanism of lined rock cavern for compressed air energy storage power station

Lined rock cavern is one of the popular gas storage forms for compressed air energy storage power station. The theoretical analysis of mechanical response of lined rock cavern under high internal pressure is helpful to understand the load-sharing principal among steel lining, concrete lining and surrounding rock. In this article, an analytical solution, considering the plastic deformation of surrounding rock and concrete lining, is derived. The load-sharing principal is revealed based on the analytical solution. The load-sharing ratio of each component depends on the quality of surrounding rock. The main body carrying the gas pressure changes from the surrounding rock to the combining of rock and steel lining, when the quality rank of surrounding rock changes from II to IV. Meanwhile, the load-sharing ratio of steel lining increases with the plastic zone of concrete lining and surrounding rock expanding. Subsequently, the influences of the mechanical and geometric parameters of surrounding rock, concrete lining, and steel lining, and the in situ stress on the stress of steel lining are discussed. Finally, the feasibility of the design method referring to ‘Design Specification for Steel Penstocks of Water Conservancy and Hydropower Engineering’ is discussed by comparing its results with these from the analytical solution.