Abstract:
Rocks in the deep subsurface are often in a complex geological environment, and physical and mechanical behavior of the complex geological environment makes the rocks multivariate. Experimental research for the clay rocks from a mine on the thermo-hydro-mechanical coupling characteristics and acoustic emission is conducted, and the characteristics of deformation, infiltration, damage and acoustic emission of the clay rocks in different geological environments are analyzed. The results show that temperature and confining pressure have obvious damage degradation and inhibition of deformation for the specimen, and the higher the temperature, the greater the confining pressure is, and the specimen are gradually from brittle fracture to brittle ductile fracture transition. The corresponding Yu Yanshi volume changes with the change in permeability, resulting in four stages of “reduction-balance-increase-fall”. The volume change and mutation point to the ring strain correspond to the permeability accelerated boundary. Under the high confining pressure and temperature, the AE is characterized by “high amplitude”, and the gradient feature is not obvious, and the most active value is lag. Under low temperature and low confining pressure, the acoustic emission has obvious characteristics of the maximum gradient. The maximum value exists in the vicinity of the peak. Under the same confining pressure, the permeability damage value increases with the increasing temperature, and the greater the confining pressure, the less the permeability damage value is. The higher the temperature and the greater the confining pressure, the more uniform the damage is.