Strength characterization for rock under multiaxial stress states

A phenomenological strength criterion for brittle polycrystalline materials in multiaxial states of stress is proposed. This criterion allows the strength estimation practically for any combination of principal stresses in triaxial, as well as in biaxial stress states. It does not contain parameters which could require additional evaluation (excluding uniaxial compressive and tensile strength data). The results agree well with available experimental data. This criterion can be used for an estimation of strength of brittle polycrystalline materials, such as rocks and concrete, for strength analysis of concrete structures and their foundations by numerical methods.