Creep-fatigue characteristics of rock salt under different loading paths

The salt behavior subjected to creep-fatigue load is meaningful ensure the stability of cavities used for underground energy storage. specimens are tested under three paths load, including creep followed by fatigue (C + F), (F C) and (CF). stress-strain curves, deformation, loading modulus acoustic emission (AE) count were systematically analyzed. axial, lateral volumetric deformations present a four-phase two-phase change trend at C F CF loading, respectively. deformation curve an individual or stage resembles that in pure tests. prior decreases strain rate subsequent phase. rock stage, presents downward with increasing cycle numbers samples loading. hold time during loading-unloading exerts little effect on variation modulus. increases irreversible each induces be prone dilate Continuous AE activities monitored while minor responses develop phase These results suggest combined sequence simultaneously result negative positive interaction between them, explained from viewpoint micro-mechanism. • Creep-fatigue tests different stress conducted salt. counts