Unified Three-Dimensional Revision of Modified Cam Clay Model

According to unified strength parameters obtained from unified strength theory, the slope of critical state line is modified to reflect critical states of different geomaterials under general stress states. Yield function that can consider the effect of the third deviatoricic invariant is proposed, and an elasto-plastic constitutive model is established by adopting non-associated flow rules; furthermore, methods of overcoming singular points on the yield surface are discussed. The proposed model is verified by true triaxial tests of clay, and results show that the model can well predict stress-strain relationships.