A discontinuous numerical model to simulate rock failure process

Abstract

Due to the difficulty of the classical fracture mechanics in dealing with multicrack coalescence, the simulation of jointed rock failure has remained a worldwide problem since the middle of the last century. Through a nearly 10-year effort, we have developed a novel but simple discontinuum-based approach, namely DDARF (discontinuous deformation analysis for rock failure), to simulate the progressive failure process of jointed rock mass. In the proposed method, by adopting the FE adaptive mesh generation technique—the advanced front method, the computational model of triangular DDA block system is automatically established. Also, the randomly distributed mechanical parameters statistically satisfying Weibull’s law are assigned to the blocks to simulate the heterogeneity of rock mass. In the generating process of the block system, numerous artificial joints come into being. These artificial joints provide the potential paths along which the cracks generate and propagate. The two blocks beside an artificial joint are glued together through adhesive algorithm, and if the glue is invalid, the artificial joint will break and turn into a real crack. In this way, the rock fragmentation process can be simulated. The results of several verification examples indicate that the DDARF method can simulate the whole process of rock fragmentation, and is suitable for cases of intact rock, rock mass with non-penetrative joints, and even blocky rock.

Keywords:

• DDA
• rock fragmentation
• artificial joint
• adhesive algorithm

Acknowledgements

Professor Gen-hua Shi kindly provided a great deal of help and guidance and is specially acknowledged.

Funding

This work was supported by the Major State Basic Research Development Program of China (973 Program) [grant number 2011CB710602], the China National Natural Science Foundation [grant number 40972201], the Independent Research Key Project of State Key Laboratory of Geomechanics and Geotechnical Engineering [grant number SKLZ0801], and the Independent Research Frontier Exploring Project of the State Key Laboratory of Geomechanics and Geotechnical Engineering [grant number SKLQ001].