Stability Analysis of Rainfall-Triggered Toe-Cut Slopes and Effectiveness Evaluation of Pile-Anchor Structures

Slope toe excavation strongly influences the stress balance of natural slopes and redistributes the stress of the slope body. Consequently, the sliding failure of toe-cut slopes is increasingly becoming more frequent, particularly in regions with persistent rainfall. The effects of external factors, namely, toe excavation and persistent rainfall, which lead to toe-cut slope failure were investigated through the numerical analysis of typical toe-cut slopes in the southeastern coastal region of China. Based on the grey relational theory, sensitivity analysis was carried out on the controlling factors to determine the degree of influence exerted by the external factors on the stability of toe-cut slopes. The stability analysis of toe-cut slopes reinforced by pile-anchor structures under earthquake conditions was carried out using pseudo-static analysis. The safety factor of toe-cut slopes significantly decreases as the excavation height, rainfall duration, and rainfall intensity increase. The slope stability is more sensitive to the excavation height of a toe-cut slope than it is to rainfall. The stability of a toe-cut slope reinforced by a pile-anchor structure was also analyzed under rainfall and earthquake conditions using the limit equilibrium method and pseudo-static analysis, respectively. The slope stability significantly improved when the slope was reinforced by a pile-anchor structure, even when the slope was subjected to persistent rainfall and earthquakes. The findings of this study can provide important guidance for the prevention of geological disasters in mountainous areas.

Automated summary

The stability of toe-cut slopes is significantly affected by external factors, with rainfall having a smaller impact compared to excavation height. Reinforcing toe-cut slopes with pile-anchor structures can effectively improve stability under rainfall and earthquake conditions. This study provides important guidance for the prevention of geological disasters in mountainous areas.