基于微裂纹演化的岩石蠕变损伤与破裂过程的数值模拟.

The traditional phenomenological creep models，which ignore the physical mechanisms of time-dependent fracturing in rocks，are not adequate to replicate the realistic creep behavior of rocks under complex loadings. In this study，a dual-scale model was proposed to represent the realistic rock medium in the framework of continuum mechanics. In addition，based on the mechanisms of time-independent and time-dependent growth of microcracks，the theories of damage mechanics and fracture mechanics were employed to develop the micro-crack based damage constitutive equations and failure criterion at the micro-scale. The obtained governing equations were programmed with Matlab and Comsol，which are capable of capturing the time-dependent damage and failure process of rocks. Furthermore，a bi-axial compressive creep test was performed and the numerical results show that the proposed model replicates the typical tri-modal creep behavior and the time-dependent fracturing in rocks. The proposed model provides a useful approach to further investigate the long-term stability of rock engineering and to predict the geological disasters. [ABSTRACT FROM AUTHOR]