An Improved Dilatancy Boundary for Salt Rock

Salt layers and domes have been used to store hydrocarbons and to dispose of nuclear wastes. One of the most important properties of rock salt is its good deformability, which can neutralize the deviatoric stress and heal damage. Structural stability is one crucial requirement in salt cavern design and construction. Various criteria and methods have been proposed for salt cavern design and stability analysis. This paper investigated the advantages and limitations of various stability criteria. The results suggest that the stability criterion proposed by De Vries et al. is the most suitable approach for stability analysis. However, the effects of the stress path and history are not considered in this criterion. To overcome this shortcoming and to integrate effects of the stress path and history within the criterion, an updatable dilatancy criterion is proposed. In the proposed dilatancy criterion, a representative parameter is defined based on the healing and damage that occurred in a previous cycle of loading and unloading, which takes into account the stress path and history and their effects on the behavior of rock salt in subsequent cycles. The new criterion gives deeper insight into the strength of rock salt based on previous damage-healing background, and is useful in appropriate design and operation of salt cavern. (c) 2023 American Society of Civil Engineers.

Automated summary

Rock salt's good deformability is one of its most important properties, which can neutralize stress and heal damage. Stability is a crucial requirement in salt cavern design and construction. This paper investigated various stability criteria and found that the criterion proposed by De Vries et al. is the most suitable approach for stability analysis. However, it does not consider the effects of stress path and history. To address this, an updatable dilatancy criterion is proposed which takes into account the stress path and history and gives deeper insight into the strength of rock salt.