Numerical simulation of the mechanical behavior of rock mass with different scale flaws and its application

摘要

The rock mass contains the macroscopic and mesoscopic flaws at the same time, and therefore, how to accurately assess their co-effect on the rock mass mechanical behavior is still an important and difficult issue. The elastic-brittle model and Null model in FLAC(3D) code are adopted to describe the mechanical behavior of the intact rock and pre-crack, respectively, and the superfine element division method is also adopted to mesh the numerical model to simulate the rock mass failure. Meanwhile, a new method to generate the mesoscopic flaws is proposed which can be determined with the rock mass void ratio. Then, the effect of the mesoscopic flaws on the rock mass mechanical behavior is studied, and at the same time, the effect of the pre-crack dip angle and length on the rock mass mechanical behavior is also studied. Finally, the proposed method is adopted to study these two kinds of flaws on the factor of safety and critical failure surface of the rock mass slope. The results indicate that the macroscopic flaws play a control role in the failure mode and compressive strength of the rock mass under uniaxial compression. They also control the failure mode and the factor of safety of the rock mass slope. Meanwhile, although the mesoscopic flaws do not change the control role of the macroscopic ones on the mechanical behavior of the rock mass, they do have some effect on this control role. Finally, the physical test is done to verify the numerical results.