摘要
The riverbed overburden for dam foundation in Doutankou hydropower station can be divided into four layers or three groups from top to bottom according to its grain composition and structure,physical and mechanical properties and difference from engineering characteristics.By comprehensive analysis and judgment from many factors,the layer of silt and fine sand with gravel is none of liquefaction under vibration,the layer of silty clay is of high compressibility,and the other two layers containing boulder and sand gravel are of strong to more strong water permeability,which will result in the problem of leakage.Under the head of water and seepage pressure,the seepage stability of last two layers is bad,and necessary impervious measures are needed.