Luo, W, Zhang, P, Zou, Y & Johansson, D 2024, 'Pilot numerical analysis for geometry optimization of lined rock cavern', in Daniel Johansson & Håkan Schunnesson (eds), MassMin 2024: Proceedings of the International Conference & Exhibition on Mass Mining, Luleå University of Technology, Luleå, pp. 1056-1065.
(https://papers.acg.uwa.edu.au/p/2435_G-17/)
Abstract: Lined rock caverns are an innovative solution for underground gas storage. Inspired by the design of lined rock cavern (LRC) in Skallen, Sweden, concerns arise about potential stress concentration regions within cavern liners since they pose challenges to the long-term stability and safety of LRC. To improve the liner stability, the shape optimization of LRC was explored preliminarily through numerical modelling that included all key components, i.e., the rock mass, concrete and steel liners, and the sliding layer between them. Besides Skallen's original design, three additional steel liner shapes were proposed. Their performance under certain internal pressures was assessed based on the distribution of stress in the steel liner and displacement in the sliding layer. Due to the lack of confirmed data, two different groups of mechanical parameters of the sliding layer were compared. One set was derived through calibration, using displacement data monitored in the field within the sliding layer, while the other reflected the condition that steel liner contacts concrete liner directly. It is found that stress and shear displacement concentration typically occur at the invert corner of steel liner. This issue can be significantly mitigated by using a junction with smooth transition, such as the shape with a semi-circular bottom. Moreover, the impacts of the liner shape on the stress concentration become more pronounced when the sliding layer is more rigid. The results improve the understanding of the interaction effects between the sliding layer and steel liner, thereby enhancing the feasibility and reliability of further optimal LRC design.