The evolution of toppling deformation of anti-dip slope is essentially a process of energy dissipation and transformation. Aiming to study the characteristics of energy evolution in different stages, the DEM (discrete element method) software PFC (Particle Flow Code) was utilized to establish a two-dimensional numerical model for a bank slope in Chongqing based on geological background data and field investigation. The DEM model was proven to be reliable not only because the deformation discrepancy between the numerical model and actual bank slope was not large but also because some obvious fractures in the actual bank slope can readily be found in the numerical model as well. In this article, content about displacement in the shallow layer was analyzed briefly. Special effort was made to analyze the energy field and divide the toppling deformation process into three stages. (1) Shear deformation stage: this is an energy accumulating stage in which the strain energy, friction energy, and kinetic energy are all small and the deformation is mainly shear deformation in the slope toe. (2) Stage of main toppling fracture surface hole-through: all three kinds of energy present the increasing trend. The shear deformation in the slope toe expands further, and the toppling deformation also appears in the middle and rear parts of the bank slope. (3) Stage of secondary toppling and fracture surface development: strain energy and friction energy increase steadily but kinetic energy remains constant. Deformation consists mainly of secondary shearing and a fracture surface in the shallow layer. Secondary toppling and fracture surface develop densely.

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There are a large number of granular slope mixture geological disasters in the alpine mountainous areas in western China. Their structural characteristics are significantly different from the general slopes. They have the characteristics of poor self-stability, high suddenness and strong recurrence. With the continuous development of the western region of the country, such geological disasters have received close attention from scholars at home and abroad. This article first summarized and analyzed the basic characteristics of the typical domestic granular mixtures slope accidents, and understood the basic characteristics of disaster. Then the domestic and foreign research progress from the aspects of governance measures were summarized. Finally, based on the summary of typical granular mixtures slope disasters and research status, the existing problems in the current research were analyzed, and the key points and difficulties of future research had prospected. The research results have important theoretical significance for the treatment of granular slope.

More and more underwater-related geotechnical problems have arisen, but there is little research about the instability process of submerged anti-dip slopes. This study built the CFD–DEM coupling method based on the CFD solver OpenFOAM and the DEM solver PFC. The Ergun test was selected as the benchmark test to verify the accuracy of the coupling method, and the pressure drop predicted from the coupling method agreed well with the analytic solution. Then, we built a numerically submerged anti-dip slope model, and a special effort was made to study its instability characteristic. The flow of water will weaken the slope stability, and the birth of cracks will be accelerated. The drag force will restrain the toppling deformation, resulting in a deeper fracture surface. Then, we changed the joint thickness and joint angle to study its effect on slope stability. The collapse load increases with the joint thickness, and the form of toppling deformation changes from flexural failure to block failure. The collapse load increases with the decreasing joint dip, and the position of the damaged area becomes higher; the angle between the bottom fracture surface and the vertical line to joints becomes smaller with the decreasing joint dip.

In order to study the effect of elastic modulus of rock mass under deep crustal stress on blasting failure characteristics and damage mechanism, this paper simulates rock blasting with different elastic modulus through particle flow software. The blasting failure characteristics of rock mass are obtained by reading the peak stress changes from the measuring points. The damage mechanism of rock blasting is revealed from the aspects of crack distribution, crack development trend, fragment formation. The results show that: As the elastic modulus increases, the peak stress of each measuring point is gradually decreasing; with the increase of elastic modulus, the macro cracks of rock mass become shorter after blasting; when the elastic modulus is 48 GPA, the number of cracks is the largest and the development is relatively gentle.