Physical Modeling for Large-Scale Landslide with Chair-Shaped Bedrock Surfaces under Precipitation and Reservoir Water Fluctuation Conditions

The deformation and failure mechanisms of historical landslides, characterized with different types of bedrock surface shapes which are known to have been induced by rainfall and reservoir water fluctuations, is an important issue currently being addressed by many researchers. The Zhaoshuling Landslide of the Three Gorges Reservoir Region, which was characterized with a chair-shaped bedrock surface under rainfall and reservoir water fluctuation conditions, was selected as an example in this study's physical modeling process. The results of different parameters, including the displacements, pore water pressure, and total soil pressure during the landslide event, revealed that the Zhaoshuling Landslide with a chair-shaped bedrock surface had been extremely sensitive to heavy rainfall coupled with the rapid lowering of the water levels. Then, based on the data analysis results of the monitoring of the rainfall and groundwater levels, as well as the reservoir water levels, a conceptual model was put forward to explain the failure mechanisms. It was believed that the chair-shaped bedrock at the toe of the slope had been subjected to a localized zone of high transient pore water pressure, which had significantly adverse effects on the mechanisms of the slope stability.