Simulating the failure mechanism of rock slopes (due to kinked and secondary cracks propagation) by a higher order displacement discontinuity method

摘要

Numerical modeling of rock slopes is now used routinely in the civil and mining engineering sectors as well as in academic research of numerical applications available today. The stability of rock slope is mainly determined by its discontinuity and Rock Bridge. However, the failure mechanism of discontinuity and Rock Bridge has not been studied comprehensively. In this paper, the stability analysis of jointed rock slope is carried out by kinked and secondary cracks propagation using the higher order displacement discontinuity Method. This study presents a new approach for stability analysis of jointed rock slope. It can also consider the complicated geological conditions and supported slopes. Fracture mechanics is the field of mechanics concerned with the study of the formation of cracks in materials. Previous researches have shown that Griffith's brittle fracture theory can be modified to account for the effects of crack closure in compression. They have also shown a useful basis for the study of the fracture of hard rocks based on the modified Griffith theory. An analysis of the stress distribution around a crack indicates the points of fracture initiation as well as the initial direction of crack propagation. As a result of the changes in stress distribution associated with fracture propagation it is, however, impossible to predict the final path of the propagating crack. Consequently, a serious limitation of the Griffith theory lies in the fact that it can only be used to predict fracture initiation. Recently, several researches have shown that the Mode II fracture toughness of rock material is usually higher than the Mode I fracture toughness, especially when the confining pressure increases.