Characterization and Application: Tri- parameter Strength Criterion for Rocks Based on Ultimate Stress Ratio

Abstract

Abstract To precisely analyze the yield and failure laws of rock materials under complex stress states, a new multi-parameter strength criterion for rocks characterized ultimate stress ratio considering the effects of hydrostatic pressure and principal stress based on the du-τ2 strength theory is proposed. To verify the applicability and rationality, the test data of five rock materials under complex stress states and the H-B criterion are experimentally and theoretically compared with the criterion. The results show that the strength criterion has strong flexibility, and the shape of the yield curve in the π plane varies between ellipse and hyperbola, because the parameters are determined by the material's own ultimate stress ratios, and the Tresca criterion and Mises criterion is only a special case of this criterion; the principal stress space is approximately conical; the theoretical curve agrees better with the experimental data of various rock materials than the H-B criterion; the new theory is feasible and supplementary to the development of strength theories and has great theoretical significance and application value. 1. A new multi-parameter rock strength criterion was proposed, incorporating the influence of confining pressure and principal stresses, characterized by the limit stress ratio, demonstrating significant flexibility. 2. Through experimental data validation, this criterion exhibits better applicability in describing the yield and failure behavior of rock materials under complex stress conditions, proving to be more rational compared to the traditional H-B criterion. 3. This research provides a novel theoretical foundation for rock material strength theory, holding significant theoretical implications and practical value for applications in rock engineering and geology.