高地应力区复杂结构河谷应力场特征——以锦屏Ⅰ级水电站为例  

Stress Field Characteristics of a Valley Slope with Complex Geological Structure in High Geo-Stress Area:A Case of Jinping First Stage Hydropower Station

作　　者：徐佩华[1,2] 黄润秋[2] 陈剑平[1] 袁中凡[1] 

机构地区：[1]吉林大学建设工程学院,长春130016 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《吉林大学学报（地球科学版）》2013年第5期1523-1532,共10页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(41130745);地质灾害防治与地质环境保护国家重点实验室开放基金项目(GZ2009-21);国家博士后基金项目(20070411147)

摘　　要：以锦屏Ⅰ级水电站为例,在实际地质调查基础上,分析整理实测地应力数据,以数值模拟为手段,对高地应力区复杂结构谷坡应力场特征进行了研究。结果表明:高地应力区具有复杂结构的河谷,遭受河谷快速下切改造后,其谷坡应力场存在"四区"分布特征,即应力降低区、应力过渡区、应力增高区及原始应力区;背景构造应力和河谷形态特征是导致谷底高地应力现象出现的2个重要因素;谷坡内的软弱带对应力场分布产生重大影响,尤其是倾坡外断层的存在,更易于谷坡应力卸荷,这是导致锦屏左岸深卸荷形成的重要原因,以及导致左岸卸荷基准面高程低于右岸的原因之一;河谷下切过程中,右岸顺倾岸坡发生应力调整的坡体范围比左岸的反倾岸坡大,因此其原始应力区在更深的深度内才出现。简单探讨了锦屏深裂缝的成因机制,认为河谷迅速下切导致的快速卸荷是锦屏深裂缝形成的原因之一。Jinping first stage hydropower station was taken as the research area to study the stress field characteristics of a valley slope with complex geological structure in high geo-stress area. According to the analysis on Jinping valley stress field features, the valley slope stress was classified into four zones, namely, the stress-releasing zone, stress-interim zone, stress-concentrating zone and stress-stable zone. The tectonic stress and the morphology of valley shape were two important factors that cause high stress at the bottom of valley. The faults in valley significantly influence the stress field characteristics. The valley stress was more easily unloaded through the fault tending outward, which was one of the reason for the unloading limitation altitude was lower in left bank than right bank and deep unloading zone in left bank slope. The slope range influenced by geo-stress state adjustment during the river cutting was wider in right bank than in left bank. The rapid unloading because of river rapid cutting was one of the reasons that induced the

关 键 词：锦屏Ⅰ级水电站 河谷应力场 高地应力 复杂地质结构 应力 

分 类 号：P642.3[天文地球—工程地质学]