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Abstract Height difference between the crown and the toe of rupture surface of Zhaizicun landslide in Jinsha river is 638 m，with about 2.5×108 m3 total rock displaced. The width of crown cracks surrounding the main scarp，which is limestone cliffs with a height of 5–30 m，is 30–100 cm. Slip source area with gullies is covered by colluvial deposit with vegetation，talus and separate giant rock blocks with a diameter of 1–6 m. The landslide occurred in Chenghai fault zone，which developed in the limestone dating to C2+3；and the landslide deposit is mainly made of cataclastic limestone and karst breccia. The Zhaizicun landslide once dammed Jinsha river and the crest of the residual landslide dam with a volume of 180 × 104 m3 opposite slip source area is 118 m high above the river. The relic landslide dam is mainly composed of 70% of limestone block with a diameter of less than 30 cm and 30% of blocks of limestone and karst breccia with a diameter of more than 30 cm. Chenghai fault zone with a length of 200 km is normal and lithospheric fault and its long-term activities make the quality of the rockmass in fault zone decrease. The undercutting of the Jinsha River flowing along the left side of the fault zone make the right bank slope increasingly steep and laid the foundation for the bank slope failure on a large scale. Chenghai fault zone is an activity fracture and the earthquake caused by its own activities is the inducing factor of Zhaizicun landslide.
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Received: 29 December 2010
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2011, Vol. 30 
