某水库溢洪道边坡变形破坏特征及治理对策研究

通过对边坡变形特征的分析,研究了由粉砂质泥岩、泥质粉砂岩、炭质页岩互层组成的斜向坡高边坡的变形破坏模式,基于模式分析提出了有针对性的治理措施.在工程地质条件分析的基础上,通过不同部位裂缝、岩体松弛及层间错动现象的分析,认为边坡的变形受层间错动带及陡倾坡外卸荷裂隙控制作用明显,边坡中上部沿层间错动带产生拉应力及剪应力集中,边坡下部软岩产生压缩变形,引起块体向坡外及岩层倾向方向的变形,并通过层面和卸荷裂隙向上传递变形,其变形破坏模式表现为阶梯状蠕滑-拉裂变形.由于边坡下游侧为强风化强卸荷带碎裂结构岩体,存在多条软弱夹层,可产生多处潜在剪出口,因此边坡的治理以削方减载为主,并通过预应力锚索框架控制层间软弱夹层的变形.

Deformation character and the control method of spillway slope at some reservoir

This paper presents the failure model of some diagonal slope with the interlayered silt mudstone, argillaceous sandstone and carbon shale by analysing the slope deformation character. By analysing cracks, rock mass relaxation and interlayered strain-slip in the slope and based on the engineering geological conditions, the authors indicate that the deformation of the slope is controlled by weak interlayers and steep dip off-load cracks. Tension stress and shear stress have concentrated in the weak interlayers, and the soft layer in the slope bottom has been compressed. This cause blocks formed by weak layers and off-load cracks moved to the dip direction of the slope and rock layers. The deformation develops along rock layers and off-load cracks resulting in the stepladder-like creep and crack deformation of the diagonal slope. Because there are cataclastic rock mass weathered and offloaded with many weak interlayers in the slope of the lower reaches of the river, the potential landslide may destroy the weak layers. The control of the slope deformation should concentrate on offloading the cataclastic rock mass and controlling the deformation of weak layers by the prestressed anchor wire.