Computed tomography analysis on cyclic fatigue and damage properties of rock salt under gas pressure

In this work, a series of fatigue tests combining cyclic loading and gas pressure on rock salt using the computed tomography (CT) scanning method was performed. Fatigue life under gas pressure showed a downward trend compared to the cases without gas pressure. Gray scale histograms could be used to reflect intuitively and accurately the propagation of damages inside rocks. Fatigue life and gas pressure followed a logarithmic relationship. Due to the wedge effect of gas pressure, gas could penetrate into the crack tips or pores, thus accelerating the development of micro-cracks during the cyclic opening and closure.