Effect of Triaxial Loading and Unloading on Crack Propagation and Damage Behaviors of Sandstone: An Experimental Study

In the current study, a series of laboratory triaxial loading and unloading experiments were conducted for the purpose of comprehensively understanding the effects on sandstone of loading processes under axial stress conditions and unloading processes under confining pressure conditions. The mechanical properties and crack propagation behaviors of sandstone specimens were analyzed. In addition, a new damage variable based on crack evolution was...