A COMPARISON STUDY OF ROCK STRENGTH CRITERIA CONSIDERING TENSILE STRENGTH

Most studies on rock strength criterion usually focus on the compressive strength, paying little attention to the tensile strength. However, as one of the most important mechanical properties of rocks, tensile strength is a key parameter in rock engineering design. Based on laboratory experimental data of five types of rocks, four strength criteria were assessed. The comprehensive evaluation of strength criterion was compared with the test results in terms of the precise description of the tensile strength, the minimum average standard fitting deviation and the main stress fitting curve. Effects of different strength criteria on the prediction of tensile strength were investigated. Results showed that, compared with other three strength criteria, the exponential strength criterion was the closest to the test values with the best precision. Therefore, exponential strength criterion is recommended to evaluate rock strength characteristics under different stress states.