Stability analysis of the chonggang landslide in the reservoir of Three-Gorges, china

The Chonggang landslide, is located at uppermost of the reservoir of Three-Gorges about 640 kilometers away from the dam which will be completed in 2008. Main industrial foundation construction of the Chonggang iron and steel company from the latest of 50's to the earliest of 60's triggered a series of reactivation in the front of landslide. A new turn of thorough geological studies was completed during 1994 to 1996 for risk analysis concerning future influence from impoundment of the reservoir. Stability analysis along different profiles reveals always safety factors larger than 2, which hardly explains the mobilization of landslide. Important geological discovery of a IO-centimeter thick soft intercalation in rich of montmorillonite plays dominant role for explaining the mechanism of this large translational landslide fully controlled by horizontal sedimentary bedding.