Study of time-variant system reliability analytical method for underground salt rock storage group with multiple failure modes during operation period

Underground salt rock storage cavern is widely used for its good sealability and safety performance, but the research on its system reliability and risk is still at the exploratory stage. Based on the system reliability analysis theory, the failure of storage group is defined in this article. Considering the influence of the cavern s volume shrinkage and pillar s plastic zone development resulting from salt rock s creep property during operation period, the multiple failure modes of the storage group are given and the system reliability mode is built. Considering the correlativity of different elements and using the weakest failure mode assumption, the time-variant system reliability of underground salt rock storage group is analyzed. Based on Jintan salt rock storage group, a salt rock storage group numerical model is established and its time-variant system reliability is studied, and some valuable conclusions are obtained. A method of time-variant system reliability analysis is proposed and the result can provide reference for the safe operation and stability evaluation of the salt rock storage groups.