Probability-based structural design of lined rock caverns to resist high internal gas pressure

Abstract

This paper describes a probability-based structural design approach to underground, lined rock caverns for the bulk storage of pressurized gas, such as compressed air, compressed natural gas, or compressed gaseous hydrogen. Our design approach is based on a combination of a point estimate method and a deterministic numerical analysis code. In the present study, we demonstrate the validity of this numerical approach in the design of underground structures by comparing it with a theoretical solution for a lined-tunnel problem. Our design approach is then applied to the preliminary structural design of a lined rock cavern for storing compressed natural gas at a high pressure of 15MPa, where structural support for ensuring gas-tightness and the cavern's mechanical stability is supplied by both steel and concrete liners. In this application, a probability-based design chart for determining the strength and thickness of the steel liner is presented, and the structural performance of the concrete liner is evaluated in a probabilistic manner.