Study on rock energy storage limit evolution model and strength criterion

Strength theory serves as the foundation for disaster prevention and control in geotechnical engineering, but the applicability of classical strength theories under complex stress states still has certain deficiencies. Focusing on the evolution mechanism of rock energy storage limit, and based on the existing theory, the evolution model of rock energy storage limit under complex stress state is established by introducing parameters <italic>λ</italic> that can reflect the influence of Lode angle. The analysis of four special stress states reveals the phenomenon of unequal tensile and compressive strength of rocks and possible failure under hydrostatic pressure. Based on the rock energy storage limit evolution model, a new rock strength criterion is established, which can be degenerated into the D-P strength criterion, and effectively addresses the deficiencies of the D-P strength criterion, namely the lack of Lode angle effect and the oversized tensile-shear region. Verification using true triaxial experimental data of four types of rocks shows that the newly established strength criterion exhibits high calculation accuracy, with an average error ranging from 2% to 12%, while the D-P strength criterion exhibits an average error ranging from 18% to 51%. Compared with other strength criteria, the strength criterion established from the perspective of rock energy storage limit has clear physical meaning and high accuracy, which holds reference significance for the study of rock failure behavior.