某水电工程进水口岸坡深部拉裂的成因探析

Study on genetic mechanism of a deep tensile fracture at inlet slope of a hydropower project

在高山峡谷地区修建水库 ,岸坡卸荷拉裂问题是经常遇到的工程地质问题。文章针对雅砻江某大型水电工程 ,在统计分析了大量勘探资料的基础上 ,讨论了位于左岸进水口岸坡的深部卸荷拉裂的成因机制 (受结构面控制 ) ,并对其稳定性作了初步评价。结果表明 :虽然目前卸荷拉裂现象比较突出 ,由于没有足够的空间 ,尚未发展到倾倒变形的程度 ,而且缓倾角结构面不发育 ,不致构成滑移 拉裂破坏模式 ,但有可能与中倾角结构面组合构成不稳定块体。

Deep tensile fractures always occur in slopes of reservoirs constructed in high mountains or deep valleys.Taken a large scale hydropower project of Yalongjiang River as an example,large amount of exploration data has been statistically analyzed,and the genetic mechanism (controlled by geologic structural surface) of the deep tensile fracture at inlet slope has been discussed.Meanwhile the stability of the slope is preliminarily evaluated.The results reveal that the development of the deep tensile fracture does not lead to rock fall at inlet slope because there are no enough spaces,but possibly develope to unstable block with middle tectonic discontinuities.