Advances in Rock for Intermediate Principal Stress Effect and Strength Theory

Authors firstly summarized the advances in rock of the intermediate principal stress effect test and strength theory,then found out some basic laws of the intermediate principal stress effect for rock,and characteristics and shortcomings of the existing rock strength theories.Finally,authors introduced the unified strength theory,and its prediction for rock true triaxial tests and applications in geotechnical engineering.The study results show that the intermediate principal stress effect and its range is an important characteristic for rock strength and has been considered as one basic problem for proposing a new failure criterion;a better solution more consistent with actual situations can be obtained by using unified strength theory with taking combined effects of more complex factors into account.