Centrifuge model test and numerical simulation on evolution characteristics of fracture surface of the anti-dipped layered slope

The formation and evolution characteristics of fracture surface is one of the key points in anti-inclined layered slope research, and it is also the basis of stability evaluation as well as engineering design and treatment. In this study, the stress and deformation parameters of the slope are obtained by using the indoor large-scale geotechnical centrifuge. At the same time, combined with the PFC numerical simulation results, the formation and evolution process and characteristics of the slope fracture surface are displayed: firstly, the compression shear crack is generated and extends to the middle and lower part of the slope, and the compression shear zone of the slope is divided; secondly, the developments of cracks toward to the middle and upper part of the slope, and with the initial formation of fracture surface, the deep slope body is bent; finally, the shallow cracks are completely connected to form a complete fracture surface Ⅰ from the top to the foot of the slope. The middle and upper parts of the internal potential fracture surface (Ⅱ, Ⅲ) are approximately parallel to the slope surface, and the lower parts are merged gradually at the foot of the slope. While the potential fracture surface Ⅳ at the boundary between the stable compression area and the bending area is stepped. At the same time, there are three secondary fracture surfaces in the shallow layer of the slope. The formation mechanism of the fracture surface is revealed that the deformation and failure of the slope causes the differential stress of the rock stratum due to the action of gravity. Under the action of compression shear, tension shear and bending, the crack initiates and expands from the tip of the prefabricated crack, and finally penetrates to form the fracture surface. Therefore, gravity is the internal reason, and the structural characteristics of slope are the basic conditions. The research results provide a basis for further research and practice of anti-inclined layered slope.