STRENGTH OF DISTURBED CLAY IN SLIDING ZONE OF CIGU LANDSLIDE AND ASSOCIATED STABILITY ANALYSIS

The Cigu landslide is located near a reservoir region.Its stability would be largely influenced after water is stored in the reservoir because the water level will be at 1/3 of the landslide slope height.Geological conditions of the landslide are complex and the progressive mechanism is toppling or slip.This paper examines the slide zone clay shear strength with different moisture contents.The test results show that the cohesion has a good correlation with the moisture content but the friction does not have a good correlation.The landslide stability before and after the storage of reservoir water is analyzed with limit equilibrium method combined with FEA under conditions of natural heavy-rain and earthquake.The numerical analysis shows that the landslide would be stable after water storage under native and rainstorm conditions,but unstable under earthquake.The factor of safety is less than 1,which indicates the landslide instable.