Modified KCC model for modelling mechanical behaviour of quartz sandstone under triaxial compression from low to high confining pressures

Abstract

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.

Keywords:

• Rock mechanics
• numerical simulation
• triaxial compression test
• quartz sandstone
• KCC model

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The granted supports from the National Science Foundation of China (Grant No. 11902069), Fundamental Research Funds for Central Universities of China (N180105031), the Young Talent Program of Liaoning Province (XLYC1807094), and the Research Project of China Railway Eryuan (no. KYY2019004(19-22)) are acknowledged. The work is partially supported by the 111 Project (B17009) and under the framework of Sino-Franco Joint Research Laboratory on Multiphysics and Multiscale Rock Mechanics.