Abstract:The stability of bedding rock slopes with weak interlayers is controlled by both weak interlayers and rock mass. Due to the poor physical and mechanical properties of the weak interlayer, it is prone to triggering landslide disasters along the bedding plane. The instability mechanism and failure mode of bedding rock slopes containing controlled faults have always been highly concerned in the field of geotechnical engineering. Based on the field investigation, taking the bedding rock slope on the right bank of a large hydropower project dam site in the upper reaches of the Yellow River as an example, a model is established using the finite element direct solution for slope stability. The interface elements are adopted to simulate the frictional sliding, opening, and closing of the structural surface. These conditions are applied to study the developmental characteristics, cause mechanism, and stability state of the deformation body under different working conditions when creep-sliding deformation and failure occur on the slope controlled by the F27 fault. It has been shown that the potential sliding surfaces composed of bedding joints as well as fault F27 are key factors in controlling slope stability. Under natural and heavy rain conditions, the overall slope is basically stable to less stable. Under earthquakes and extreme conditions, the bedding joints and the fault F27 have successively extended, expanded, and connected to form a creep slip bottom boundary, as well the trailing edge was damaged by tensile deformation. As a result, the creep-sliding destabilization occurred on the slope along medium-gentle dipping controlled structural surfaces. The engineering hazards are serious after slope instability, which requires key engineering treatments and slope reinforcement measures.
