乌东德水电站库区板岩遇水软化微观机理及强度模型研究  

Study of Micro-softening Mechanism and Strength Model of Saturated Slate in Reservoir Area of Wudongde Hydropower Station

作　　者：念红芬[1] 张春华 Nian Hongfen;Zhang Chunhua(School of Civil Engineering,Panzhihua Univ.,Panzhihua 617000,China)

机构地区：[1]攀枝花学院土木工程学院,四川攀枝花617000

出　　处：《三峡大学学报（自然科学版）》2018年第6期6-10,共5页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金(41772322)

摘　　要：针对乌东德水电站库区板岩遇水软化造成的边坡失稳问题,进行了板岩饱水软化的微观机理与宏观力学性质研究.通过开展X射线衍射和SEM电镜扫描,探索了不同饱水条件下板岩微观结构的变化;进一步通过开展单轴压缩试验,分析板岩强度软化规律.试验结果表明,板岩浸水后,内部胶结物质发生溶解,矿物颗粒破碎或者解体,孔隙率增加,使得宏观抗压强度降低.随着饱和水压力的增加,抗压强度降低,幅度约为10%,弹性模量降低,幅度约为30%,而泊松比无明显变化.板岩破坏呈现轴向多劈裂面破坏和剪切破坏特征.最后,运用多孔介质力学理论建立板岩遇水强度软化模型,其预测强度与试验结果一致.To resolve the problem of slope failure induced by slate softening during impoundment in Wudongde Hydropower Station,the softening microscopic mechanisms and macroscopic mechanical properties of water-saturated slate are investigated.At different water-saturated conditions,the microstructure characteristics of slate are examined using X-ray diffraction(XRD)and Scanning Electron Microscopy(SEM).And then the strength softening is analyzed by uniaxial compression tests.The results show that after the slate immersed into water,the cementing material would dissolve;the mineral particles would fall off;and the porosity would increases;so that the macroscopic compressive strength,would decrease by 10% and 30%,respectively.There is no change of Poisson’s ratio.The failure model of slate is characterized by axial splitting and shear failure.The strength softening model of slate is established based on mechanics of porous media.The strength predicted by the model is consistent with the experimental value.

关 键 词：微观软化机理 饱水压力 板岩 单轴抗压强度 

分 类 号：TV41[水利工程—水工结构工程]