云南虎跳峡“滑石板”岩质滑坡的基本特征与成因  

Principal characteristics and formation mechanism of plate type rock landslide in Hutiao-Gorge,Yunnan

作　　者：曾庆利[1] 张西娟[2] 杨志法[1] 

机构地区：[1]中国科学院地质与地球物理研究所工程地质力学重点实验室,北京100029 [2]中国地质科学院地质力学研究所,北京100081

出　　处：《自然灾害学报》2007年第3期1-6,共6页Journal of Natural Disasters

基　　金：中国科学院知识创新工程项目(KZCX3-SW-134);国家重点基础研究发展规划项目(2002CB412701)

摘　　要：1996年10月28日云南虎跳峡左岸发生"滑石板"顺层岩质滑坡。滑坡体呈不规则菱形,长800多m、宽250m、厚30多m,体积不小于500万m^3,高速下滑300多m入金沙江,并堵江成坝。通过详细野外调查和室内资料对比分析,发现该段斜坡系由内外两层结构组成,内层为原生节理的层状结构,外层为节理裂隙化松散结构。揭示了虎跳峡滑石地段斜坡发生滑坡的复杂成因机制,认为该滑坡是在玉龙—哈巴雪山断块强烈隆升背景下,地震、降雨和深切峡谷的强卸荷改造等地球内、外部动力耦合作用的结果。最后对该段斜坡的稳定性进行了初步评价,认为将来还可能再次发生类似岩质顺层滑坡,其周期长短则受内外动力的联合控制。Plate type rock landslide occurred on the 28^th, October 1996 to the left bank of Hutiao-Gorges ,Yunnan, just 267 days after the Ms 7.0 Lijiang earthquake on 3^rd, February 1996. The landslide is about 800 meters long, 250 meters wide and 30 meter thick, appearing rhombus in geometry. The total 5,000,000 cube meters rock slid for about 300 meters into the Jinsha River and temporarily blocked the river. Through carefully field investigation and indoor data analysis, the principal characteristics and complex formation mechanism of the landslide is discussed in the paper. It is found that the slope there consists of two layers of rock mass, the outer jointed and fis- sured loose rock and the inner original joint sandwich integrate rock. The paper put forwards that the landslide results from the Coupling of the earth＇s endogenic and exogenic action, such as the strong uplift of Yulong-Haba block, seismic activities, strong unloading of alteration of deep-cut gorge and rainfall. Lastly, stability of the segment is preliminarily analysized and evaluated. It is believed that landslides similar to 1996 plate type rock landslide will occur periodically on the segment of the left bank of Hutiao-Gorges in the future. The periodicity is controlled by the coupling of the earth＇s endogenic and exogenic action.

关 键 词：虎跳峡 岩质滑坡 丽江地震 地球内外动力耦合作用 

分 类 号：P425.5[天文地球—大气科学及气象学]