Failure mechanism of gently inclined bedding slope under hydraulic driving: The case of the Jiangyuan landslide along Heda Highway

The case of the Jiangyuan landslide along Heda Highway is discussed on the basis of the engineering geological conditions of slopes and the effect of hydraulic action on slope stability. From the analyzed characteristics of hydraulic pressure on slopes, groundwater pressure is found to include three aspects: hydrostatic pressure in the posterior border cracks caused by tension, uplift force on potential sliding surface, and dynamic water pressure. Then, the mechanical model of the slope under hydraulic driving and the formula to calculate critical water height for tension fractures are developed. Subsequently, the failure mechanism of the Jiangyuan landslide along Heda Highway is analyzed. Results show that the potential sliding surface of the landslide is gently inclined and interfaced between the overlying conglomerate and underlying weathered mudstone. The sliding tendency of the slope is aggravated by the reduced anti-sliding force of tension fractures in the posterior border, the gently inclined rock interfaces connected by rainfall-induced hydraulic driving, and the excavation of the constructed highway.