Search Results (2)

In this study, statistical analysis was conducted to categorize a large number of actual typical cases and analyze the formation conditions of toppling deformation in bedding rock slopes. Based on geological prototypes and similarity theory, a bottom friction test was conducted on the toppling deformable body while considering the excavation process. Based on the deformation and failure phenomena observed in the bottom friction test model, along with the displacement curves at key points, the deformation process in steep bedding rock slopes can be divided into the following five distinct stages: the initial phase, the unloading–rebound phase, the tensile failure phase, the bending creep phase, and the bending–toppling damage phase. To evaluate the stability, a new constitutive model of the nonlinear viscoelastic–plastic rheology of rock masses was developed. This model is based on a nonlinear function derived from analyzing the creep test data of rock masses under fractional loading. Furthermore, a mechanical equilibrium differential equation for rock slabs was formulated to quantitatively describe the aging deformation and failure processes of slopes with delayed instability. Finally, a stability criterion and a quantitative evaluation model for toppling deformation slopes that considered time-varying factors were established. The stability of the model was calculated using a hydropower station slope case, and the results were found to be in good agreement with the actual situation. Full article

The construction of major hydropower projects globally is challenged by slope deformation in reservoir areas. The deformation and failure mechanisms of large rock slopes are complex and poorly understood, making prevention and management extremely challenging. In order to explore the influence mechanism of the water level variation on the deformation of steep toppling bedding rock slopes, this paper takes the right bank slope near the dam area of the Longtou Hydropower Station as an example, and field investigations, deformation monitoring, physical simulation tests and numerical analyses are carried out. It is found that the slope deformation response is obvious under the influence of the reservoir water level variation, which is mainly reflected in the change in the slope groundwater level, rock mechanical parameters and seepage field in the slope body. The toe of the slope produces plastic deformation and maximum displacement. With the increase in the reservoir water level, the plastic zone expands and the displacement increases, which leads to the intensification of the slope deformation. This paper puts forward that the deformation and failure modes of the steep and toppling bedding rock slope caused by water level variation are due to shear dislocation, bending deformation and toppling fracture. This study reveals the influence mechanism of the water level variation on the deformation of steep and toppling bedding rock slopes, which can provide theoretical support for the construction of major hydropower projects. Full article