Mechanical properties of composite segmented lining for high-pressure gas storage cavern considering shear deformation

The cracking issue of reinforced concrete linings in compressed air energy storage (CAES) underground caverns poses a substantial challenge, which is difficult to fully mitigate. To control crack widths in the concrete lining, the reinforcement rate is frequently increased to high levels, making adequate reinforcement challenging. This results in increased construction costs and decreased pressure limits for the CAES system. A segmented lining structure is proposed as a solution for high-pressure air storage caverns to address this issue. This system utilizes pre-set seams to release circumferential tensile deformation, thereby reducing tensile stress on the lining. However, shear stresses between lining segments and initial support structures also induce tensile stresses on the lining. Although tensile stresses on lining steel bars are reduced near joints (within a 15ºrange), significant stresses persist at the distant ends. Therefore, a sliding layer is inserted between the lining and initial support to minimize frictional resistance. The shear stiffness of the sliding layer significantly affects the stress distribution of lining steel bars, with lower stiffness correlating with reduced stress levels. Despite the inability of the sliding layer to achieve complete smoothness, notable stress persists on lining steel bars under high internal pressures. To further alleviate tensile stresses within the lining structure, a stratified deformation release lining structure is proposed. This involves using pre-set joints in both the lining structure and initial support, with joint locations aligned between them. Computational analyses show that adopting a composite preset joint structure in high-pressure air storage caverns reduces relative shear deformations between the initial support and lining, thereby decreasing maximum crack widths in the lining. Therefore, in cases of elevated internal pressure, a segmented concrete lining structure with a sliding layer between the lining and initial support can be used. For exceptionally high internal pressures, a composite segmented lining structure with pre-set seams for both the initial support and lining can be used to facilitate layered deformation, thereby reducing tensile stress on the lining. © 2024 Biodiversity Research Center Academia Sinica. All rights reserved.