Repeated failure of a high cutting slope induced by excavation and rainfall: a case study in Fujian, Southeast China

The slide of a cutting high slope has frequently been induced by rainfall during excavation, gradually transforming the small deformation of the slope into a large hazard. It embodies the complexity, diversity of landslide mechanism, difficulty in selection, and optimization and implementation of a control scheme. Based on the case analysis of disaster control for a typical high cutting slope, this paper firstly introduced its engineering geological model, the characteristics of deformation and failure of the repeated sliding, and the corresponding control measures. Second, the repeated deformation characteristic and failure mechanism of the high cutting slope under the condition of excavation and water-level variation were analyzed using the finite element strength reduction method. Finally, the experiences and lessons of landslide control were concluded, such as the forecasting and fixing of failure mode, identification and control of unstable factors, optimization and adjustment of supporting measures, selection and avoidance of construction timing, and management and control of engineering quality. Research indicates that the engineering excavation was a sensitive factor for slope instability, and the groundwater level caused by continuous rainfall simultaneously decreased the stability of the slope, resulting in repeated deformation. Landslide control is a systematic process of engineering risk regulation comprising qualitative judgment, quantitative calculation and dynamic assessment of slope stability, targeted optimization of landslide control schemes, reasonable plan in timing and process of treatment, strict management, and monitoring of engineering quality.