Study on Triaxial Compression Tests and Energy Analysis of Jointed Rock Mass with Rough Structural Surfaces

To clarify the way confining pressure and joint inclination affected the mechanical behavior of jointed rocks under triaxial conditions, the study engaged in conducting triaxial tests on jointed rocks with various joint inclinations, examining the effects of the two parameters from two perspectives: strength and deformation failure characteristics, and energy evolution characteristics. A damage coefficient based on elastic energy and dissipated energy was proposed for the quantitative explanation of the jointed rock stability. According to the study results, when the confining pressure is the same, the increase in joint inclination is accompanied by a "U-shaped" distribution of the strength and elastic modulus of the jointed specimens. Elevating the confining pressure can result in obviously enhanced strength and elastic modulus. The specimens have three types of failure modes: (1) global splitting failure, (2) shear failure along the joint surface, and (3) mixed failure, and the failure modes can be primarily controlled by joint inclination. The input energy ( U _tcf ), elastic energy ( U _ecf ), and dissipated energy ( U _dcf ) of the specimens all show a decreasing-to-increasing trend along with the elevated joint inclination. The energy damage coefficient χ _max is defined to qualitatively indicate the likelihood of failure in jointed specimens, which are classified into three levels based on their failure probability.