三峡库区千将坪滑坡高速滑动机制研究

2003年7月13日,三峡水库初期蓄水至135m高程30d之际,在三峡库区秭归县发生了三峡库区的第一个水库滑坡,滑坡方量达1500万m3,最大滑速达16m/s,最高涌浪达24.5m。滑坡造成10人死亡,14人失踪,摧毁129间民房以及4个工厂,致1200人无家可归。千将坪滑坡发生后,为了预测三峡库区及世界其它水库工程可能发生的同类高速滑坡,持续数年研究千将坪滑坡的高速滑动机制,通过理论分析及数值模拟,探索了千将坪滑坡的高速滑动机制,认为千将坪滑坡具有孕育高速滑坡的典型结构特征,滑坡滑带的峰残强降差是滑坡高速启动的根本原因,高陡边坡蕴藏的高势能及滑带液化是滑坡加速高速滑动的主要原因。

Study of high speed slide mechanism of Qianjiangping landslide in Three Gorges Reservoir area

The Qianjiangping landslide, located in China’s Three Gorges Reservoir（TGR）, occurred on 13th July 2003 , one month after the first impoundment to 135 m a.s.l. of TGR water level. This is the first reservoir triggered landslide in TGR. This huge landslide was a high speed dip rockslide with a volume of 15 million m3, a maximum sliding velocity of 16m/s. The maximum surge height was 24.5 m, and the sliding process was finished in less then 1 minute. The catastrophic landslide caused 10 people died, 14 people disappeared, destroyed 129 houses and 4 factories, and left 1 200 people homeless. After the landslide, the author continued research on the high speed slide mechanism in order to predict the same kind of landslide disaster in the TGR area and elsewhere in the world. On the research effort on the high speed slide mechanism seen in the Qianjiangping landslide based on geologic analysis and numerical computations, it is concluded that the Qianjiangping landslide had a typical geological structure needed to gestate a high speed landslide; the great decline in shear strength in the shear zone (from peak to residual) is the essential cause for the high initial sliding speed; and the potential energy of the high slope and the liquefaction of the shear zone accelerated the sliding.