Modified Kcc Model For Modelling Mechanical Behaviour Of Quartz Sandstone Under Triaxial Compression From Low To High Confining Pressures

It is a challenge to simulate numerically the mechanical behaviours of rocks under triaxial compression at low and high confining pressures due to the limitations of constitutive models of rock-like brittle materials. This paper is devoted to developing a modified KCC (Karagozian and Case concrete) model for numerical modelling of the mechanical behaviours of Fontainebleau quartz sandstone under triaxial compression tests from low to high confining pressures. The strength surface, damage function, and the equation of state of the KCC model were modified to account for the mechanical behaviour of the quartz sandstone due to confining pressure change as indicated by a group of triaxial compression tests. The modified KCC model was then incorporated into a finite element code to simulate rock mechanical behaviours subjected to quasi-static loading. The effectiveness of the model was verified by the classic disc splitting tests. The modified KCC model was then applied to simulate the triaxial compressive properties of the quartz sandstone. It shows that the modified KCC model can effectively simulate the mechanical characteristics of quartz sandstone under low to high confining pressures.