锦屏一级水电站左岸边坡变形监测及机制分析  

Study on Deformation Response of Left Slope of Jinping-ⅠHydropower Station Influenced by Impoundment

作　　者：何如许 裴向军[1] 刘明[1] 文旭 徐岗 HE Ruxu;PEI Xiangjun;LIU Ming;WEN Xu;XU Gang(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]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,四川成都610059

出　　处：《人民黄河》2021年第10期128-133,138,共7页Yellow River

基　　金：国家重点研发计划项目(2016YFC0401908);国家创新型集体基金资助项目(41521002)。

摘　　要：针对锦屏一级水电站左岸边坡的持续变形现象,以左岸边坡的地质结构为基础,通过表面变形监测与深部变形监测相结合的综合监测手段,对其变形机制进行分析。研究结果表明,其整体的变形机制可概括为"上部持续倾倒-深部张裂-表部锁固体松弛-下部与坝体协调"。开口线以上自然边坡倾倒变形体的持续变形主要受砂岩、板岩软硬互层以及浅表部卸荷作用控制,还受下部坡体变形调整向上累积效应的影响。左岸边坡深部变形主要是受坡体深部裂缝区的持续拉张变形及断层f_(42-9)和煌斑岩脉X所体现的非滑移式拉裂松弛变形影响,而且强支护的群锚效应明显强化、深化了对变形的作用。开口线以下人工开挖支护边坡的持续变形原因是锚墙锁固的部分坡体浅表部出现整体性侧向松弛卸荷变形。标准蓄水位附近的坡体受库水浮托力的影响较大,而抗力体边坡在蓄水之后则受到坝肩推力的影响而产生压密和抬升的周期性变化特征。In view of the continuous deformation of the left bank slope of Jinping I Hydropower Station,the deformation mechanism of the left bank slope was analyzed by means of comprehensive monitoring combined with surface deformation monitoring and deep deformation monitoring.The results show that the overall deformation mechanism can be summarized as“continuous toppling of the upper part-deep tension fracture-surface locking solid relaxation-coordination between the lower part and the dam body”.The continuous deformation of toppling deformation body of natural slope above the opening line is mainly controlled by the unloading action of sandstone,slate soft-hard interbeds and shallow surface,and is also affected by the upward accumulation effect of deformation adjustment of lower slope.The deep deformation of the left bank slope is mainly due to the continuous tension deformation in the deep crack area of the slope and the non-slip tension and relaxation deformation embodied in f_(42-9) and lamprophyre dike X.Moreover,the group anchor effect of the strong support obviously strengthens and deepens this effect.The continuous deformation of the slope supported by manual excavation below the opening line is mainly due to the integral lateral relaxation and unloading deformation of the shallow part of the slope secured by the anchor wall.The slope near 1880 m is greatly influenced by the buoyancy of reservoir water,while the slope of resisting body is affected by the thrust of abutment after impoundment,resulting in the characteristics of compaction and uplift.The monitoring results and deformation mechanism of this project can be used for reference in other hydropower projects in the future.

关 键 词：边坡 监测分析 变形机制 锦屏一级水电站 

分 类 号：TV642.4[水利工程—水利水电工程]