ISSN 1003-8035 CN 11-2852/P

    三峡库区巫峡剪刀峰顺层岩质岸坡破坏模式分析

    An analysis on the destruction mode of Wuxia scissors peak down the shore slope in the Three-Gorges Reservoir area

    • 摘要: 剪刀峰岸坡位于三峡库区巫山县巫峡左岸,全长2.1 km。受北侧神女峰箱状背斜及南侧神女溪—官渡口向斜影响,岸坡为陡倾顺层岩质岸坡。岸坡坡度45°~89°,整体为陡坡与的陡崖复合地貌;岸坡出露的第四系地层主要为崩坡积碎块石土,出露的基岩含三叠系大冶组三段、四段及嘉陵江组一段至四段地层,地层多元化;岩组类别主要为大冶组及嘉陵江组碳酸盐溶岩组成的坚硬岩组及嘉陵江组二段岩溶角砾岩组成的较软岩组;岩体结构从极薄层至巨厚层状,岸坡地形、地层、岩组及结构复杂。岸坡上游至下游,2.1 km范围内,坡体结构变化大,岸坡变形破坏特征差异大,成因机制及破坏模差异大。根据岸坡不同的地质条件及特征,划分为6个大段、6个亚段。研究从岸坡宏观变形、破坏特征出发,将岸坡目前的变形、破坏总结为“构造切割及卸荷”“局部压裂、滑移”“地表溶蚀”“消落区岩体劣化”四个方面,并从岸坡成因机制上分析了各段的破坏模式。此外,本次研究还分析了库水位以上岸坡及库水位消落区的岩体劣化特征,从岩体劣化的角度提出了沿层面渐进式松脱滑移、沿软弱夹层溃屈滑移、沿“X型”节理滑移、沿层面倾倒溃屈四种岩体劣化及破坏类型。

       

      Abstract: Scissors peak bank slope is located in the left bank of Wushan gorge in the Three Gorges Reservoir area, with a total length of 2.1 km. Influenced by Shennv peak box anticline in the north and Shennv Xi-Guandukou syncline in the south, the bank slope is steeply sloping bedding rock bank slope. The slope of the bank is 45°~89°, and the whole is a composite landform of steep slope and steep cliff.The quaternary strata exposed on the bank slope are mainly cluvial gravel soil, and the exposed bedrock contains the strata of the 3rd and 4th members of the Triassic daye formation and the 1st to 4th members of the Jialingjiang formation. The strata are diversified.The rock groups are mainly hard rock group composed of carbonate lute of Daye formation and Jialingjiang formation and soft rock group composed of karst breccia of the second member of Jialingjiang formation. The rock mass structure ranges from very thin layer to very thick layer, and the slope topography, stratum, rock group and structure are complex. Within a range of 2.1 km from upstream to downstream of the bank slope, the slope structure changes greatly, the deformation and failure characteristics of the bank slope vary greatly, and the formation mechanism and failure modes differ greatly. According to the different geological conditions and characteristics of the slope, it can be divided into 6 large sections and 6 sub-sections.Based on the characteristics of the macroscopic deformation and failure of the bank slope, the current deformation and failure of the bank slope are summarized into four aspects: "structural cutting and unloading", "local fracturing, sliding", "surface dissolution", and "rock mass deterioration in the subsidence zone", and the failure modes of each section are analyzed from the perspective of the formation mechanism of the bank slope. In addition, this study also analyzed the deterioration characteristics of rock mass in the bank slope above the reservoir water level and the reservoir water level fluctuation area, and proposed four types of rock mass deterioration and failure types from the perspective of rock mass deterioration: progressive release slip along the plane, collapse slip along the weak interlayer, X-type joint slip, and toppling collapse along the plane.

       

    /

    返回文章
    返回