压缩空气储能系统衬砌岩洞的荷载分担特性：理论分析

Abstract Compressed air energy storage (CAES) is considered as a feasible approach of providing ancillary services to the power system , with the underground lined rock cavern (LRC) being a good choice for storing compressed air . Over the past decades, several old design concepts for the LRC, such as the surrounding rock mass bearing most of the internal pressure while steel lining bears less, have been proposed based on field tests and numerical simulations. However, theoretical validation about these concepts is not yet available. To overcome this limitation, based on some reasonable assumptions, a rigorous analytical model is presented in this study to prove the load-sharing characteristics of the LRC. Though a simple elastic theory is involved, the analytical model provides reliable predictions on the mechanical behavior of the LRC, as validated by comparisons with both numerical simulations and laboratory/field tests. Subsequently, a sensitivity analysis is conducted to identify primary factors with a strong influence on mechanical response of the LRC. Based on the theoretical analysis, the old design concepts for the LRC have been identified. It is found that most of the internal load is borne by the surrounding rock mass (about 80 %), followed by the concrete lining (about 17 %), with the steel lining bearing the least (about 3 %). Furthermore, several new design concepts are proposed: the thickness of steel lining can be appropriately reduced as long as the sealing performance of the LRC is maintained; high-grade concrete is not recommended for concrete lining of the LRC; rock strata with larger deformation modulus (such as 30 GPa) and higher crustal stress (such as 7 MPa) are more suitable for building an underground LRC. The deformation modulus of surrounding rock mass is the most significant factor affecting the mechanical response of the LRC, while the thickness of steel lining and the reinforcement ratio of the concrete lining have virtually no influence. The results of this study provide theoretical support for the site selection , design, and construction of the LRC in a CAES system .