Influence of composite slope geometrical parameters on soft rock slope stability

Purpose. To analyze the key parameters influencing the stability of a composite soft rock slope. Methods. Description of the key geometrical parameters of a composite slope and their influence on soft rock slope stability. Numerical simulation is performed to validate the primary effects of the key geometrical parameters of a composite slope on stability without consideration of external factors such as ground water, seismic and blasting factors. Findings. This paper put forward the influence pattern of the dumping height, excavation depth, slope angle, dumping angle, and dumping position on the safety factor of the composite slope. Furthermore, the results prove that as the dump is moved away from the reference crest or toe, the factor of safety increases. Thus, improvement of the safety factor on the critical sliding surface is defined by the area of the parallelogram. Also, when the critical position of the dump away from the edge is exceeded and the lateral pressure induced by the superimposition of the waste dump has no influence on the critical sliding surface, failure takes place in the surface mines slope and stability is relatively controlled by the mechanical strength and geometrical parameters of the surface mines slope. Originality. The paper provides a pioneering detailed description of the interactions of the key geometrical parameters of a composite slope and their influence on stability and the factor of safety. Practical implications. The results can be used for designing and stability analysis of composite slopes.