瀑布沟水电站库首右岸深部裂缝成因分析

水电工程常常建在高山峡谷地带,其天然岸坡通常由坡面向内有一个强卸荷带和弱卸荷带以及相应的强风化和弱风化带,内侧则为完整新鲜的岩石。对涉及的工程岸坡在正常卸荷带以内发育的一系列张性破裂或破裂带,称之为深拉裂缝。瀑布沟水电站库首右岸存在两个拉裂变形体,通过对其岸坡深部拉裂缝空间发育分布、变形特征的考察,综合分析造成深部裂缝发育规律与变形特征的因素。在此基础上提出,库首右岸深部拉裂缝是岸坡快速卸荷条件下浅表生改造的产物,其形成时期相当于河谷由宽谷深切为峡谷这一转换时期。

ON THE GENETIC OF THE DEEP FRACTURES OF THE PUBUGOU HYDROPOWER STATION

A hydropower station project is built on high mountain canyon tracts of which natural slope usually has a zestier of strong unloading rock and a zestier of ebb unloading and corresponding zone of strong (or ebb) weathering rock, and intact fresh rock in its inside. But there is a series of sheeted fracture or zone of fracture named as deep fracture. There are two deformable bodies on the right bank of the Pubugou hydropower station reservoir. This paper analyzes mechanisms of deep fractures and characteristics of deformation based on field investigation of the distribution characterization and deformation behavior. It is concluded that the deep fracture was caused by epigenetic reformation by release of high geostatic stresses. The formation age of the deep fracture is when the river changes from wide valley to canyon by stream trenching.