Modeling time-dependent behavior of gas caverns in rock salt considering creep, dilatancy and failure

In this paper, a numerical model of the time-dependent behavior of underground caverns excavated in rock salt is presented. An elasto-viscoplastic constitutive model is utilized to describe dilatancy, short-term failure as well as long-term failure during transient and steady state creep of rock salt. The constitutive model is employed by a Lagrangian finite element formulation to simulate the stress variation and ground movement during creep of rock salt around the cavern within the framework of large deformations. Finally, finite element analyses are provided in order to investigate the efficiency and applicability of the proposed computational model to represent time-dependent response of gas storage caverns in rock salt.

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► A creep model describing dilatancy, failure and damage was utilized.
► The constitutive model was employed by a Lagrangian finite element formulation.
► Finite element analyses of stress variations around a salt cavern was performed.
► Inelastic volumetric changes should be considered for conservative stability analyses.