三峡库区典型塌岸模式研究

三峡库区塌岸地质条件调查结果表明,不同的岸坡结构,蓄水后库岸的变形破坏形式—塌岸模式,往往差别较大。本文根据现场调查成果,结合室内分析,总结归纳出三峡库区几种典型的塌岸模式,即冲蚀磨蚀型、坍塌型、崩塌(落)型、、滑移型和流土型。在此基础上,对不同塌岸模式的发展演进过程、发育分布特征,以及塌岸与岸坡岩土结构、地形地貌等的关系进行了深入系统地研究,提出了三峡库区典型塌岸发育的一般地质条件。

TYPES OF TYPICAL BANK SLOPE COLLAPSES ON THE THREE GORGES RESERVOIR

The geological investigation at the Three Gorges Reservoir has shown that the bank slope-collapses under different riverbank structures have substantial differences.Based on the field investigation and analysis,the typical bank slope collapsess can be classified into the following five types:(a) washing and abrasion type,(b) soil collapse type including wave washing step type,backward collapsing type and cave collapsing type,(c) rock sliding type including rock block sliding type,up hard-down soft type and down concave type,(d) slope type including renew ancient slide,deep talus only superficial soil sliding type,along bedrock-cover sliding type and bedding sliding type, and(e) flowing soil type.Based on the classification,the further examination are presented.They include the evolutionary processes,,development and distribution characteristics,and relationship with soil structures,landform,and geomorphy.Finally the general geological conditions for forming typical bank slope-collapses are summarized.