某水电站坝区崩塌体特征及影响因素分析

挽近期以来，伴随青藏高原的强烈隆升，中国西南地区河谷经历强烈、快速下切，形成西南地区所特有的高山峡谷地貌，在此过程中，河谷岸坡分别遭受垂向剥蚀与侧向卸荷作用，出现一系列浅表生结构面，将岸坡浅表部岩体切割成大小不等块体，在后期时效变形过程中以崩塌、滑坡形式失稳破坏。本文以崩塌体发育部位，堆积物岩性、块度大小、风化特征等研究为基础，结合岸坡河谷演化、构造演化历史分析，追溯形成崩塌的地形地貌、地层岩性、风化卸荷、岩体结构等河谷岸坡特征。通过上述分析，总结归纳产生崩塌的主控因素是地形地貌、岩性与岩体结构，在地形地貌适合、浅表生作用强烈的区域，岸坡岩体变形破坏也较强烈，崩塌堆积物也较发育。

THE CHARACTERISTICS AND INFLUENCING FACTORS OF THE AVALANCHE BODIES AT THE DAM SITE OF A HYDROELECTRIC STATION

Since the Neoid, the river valleys in the southwestern China had been became the particular canyon-relief, wich experienced strong incision with Qinghai Tibet Plateau strongly rising. During the transformation, valley slopes suffered vertical denudation and lateral unloading effect, which caused series superficial crust structural surfaces to formation. The surface of bank slopes was incised into blocks in deferent size, and became unstability and failt in the form of collapse or landslide in late secular distortion. Studied on the position of collapse mass, lithology of deposit, block size and weathering characters, this paper, by incorporating historical analysis of superficial crust deformation and valley evolution, traced the slope characters caused collapse, just like topographies, lithologic characters,weathering and rocky structures. The conclusion is that the main factors of collapse are topographies and lithology characters. In the area of suitable relief and strongly superficial deformation, bank slope rock mass and collapse deposit deformed more strongly.