Study of the deformation characteristics and fracture criterion of the mixed mode fracture toughness of gypsum interlayers from Yunying salt cavern under a confining pressure

Based on the project background of salt caverns used for oil and gas storage in laminated salt rock, this study examined the combined mode fracture toughness, the fracture pattern, the morphological evolution of fracture surfaces, and the fracture criterion of gypsum interlayers under confining pressure. Series of laboratory tests, including fracture strength tests and scanning electron microscopy tests, were performed at four confining...