千将坪滑坡是三峡水库蓄水后发生的第一个大型基岩滑坡,引起了社会各方面极大的关注。千将坪滑坡的类型、成因演化等问题也成为学术界研究的重点和热点。本文在千将坪滑坡滑带宏观结构分析的基础上,使用层间剪切带应力历史分析方法,结合地质体铀系测年结果,得出千将坪滑坡属于新生滑坡的结论。文章研究了千将坪滑坡滑带的形成过程,分析了形成机制,指出千将坪滑带形成的地质历史成因是内外动力耦合作用的结果,建议三峡库区滑坡防治工作中要重视水库新生滑坡,特别是重视层间剪切带的研究。
With a volume of approximate 24×10^6m^3, Qianjiangping landslide, located in the Three Gorges Reservoir area, occurred on July 13, 2003. The landslide resulted in 14 people died, 10 people missing and 1200 people affected. After reservoir impoundment, the landslide was the first large rock landslide in the Three Gorges Reservoir area and brought great attention in society. In academia, problems of landslide type, genesis and evolution, etc. became the focus. With these questions, there are at least three opinions. In this paper, macrostructure of sliding zone was analyzed. According to stress history analysis and U-series dating of interbedded shear zone, formation process and mechanism of sliding zone was got. Main conclusions were as following: (i) Qianjiangping landslide was a new rockslide in interbedded shear zone; (ii) interbedded shear action induced large shear deformation of interbedded shear zone in early Epipleistocene; (iii) coupling of earth's endogenic and exogenic geologic processes is the main geological history origin. Finally, some suggestions were advanced: during the prevention of landslide, it should pay more attention to new landslides and interbedded shear zones.