三峡库区泄滩滑坡非饱和渗流分析及渗透系数反演  

Unsaturated seepage analysis and back analysis of permeability coefficient for Xietan landslide in Three Gorges Reservoir area

作　　者：魏进兵[1] 邓建辉[1] 高春玉[1] 谭国焕[2] 李焯芬[2] 

机构地区：[1]四川大学水利水电学院/水力学与山区河流开发保护国家重点实验室,成都610065 [2]香港大学土木工程系

出　　处：《岩土力学》2008年第8期2262-2266,共5页Rock and Soil Mechanics

基　　金：973项目(No.2002CB412702);中国博士后科学基金(No.20070410387);香港RGC基金(No.HKU7015/02ERGC)资助

摘　　要：泄滩滑坡的水文地质结构比较复杂,滑体、滑带及滑动影响带为多孔连续介质,透水层基岩为裂隙介质。采用等效连续介质模型模拟裂隙岩体,建立了泄滩滑坡饱和-非饱和渗流的有限元计算模型。然后采用BP网络对非饱和有限元渗流计算进行了模拟,并根据蓄水期水库水位及滑坡体地下水位监测资料,采用遗传算法对泄滩滑坡各地层渗透系数进行了反演。反演的滑体饱和渗透系数为4.89×10^-2 cm/s,与现场原位试验值1.78×10^-2～3.2×10^-2 cm/s相当;反演的滑带饱和渗透系数为4.66×10^-5 cm/s,远比室内试验值2.74×10^-7～5.73×10^-7 cm/s大。这种差异在一定程度上反映了土体参数的尺度效应。The hydrogeological structure of Xietan landslide is very complex;its slidebody,slipband and sliding-disturbed zone can be regarded as porous continuous medium,but its infiltrative bedrock is fractured.An equivalent continuum model is used to model fractured rock;and a finite element model of saturated-unsaturated seepage analysis of Xietan landslide is established.Then back-propagation neural network is used to substitute finite element seepage analysis;and saturated permeability coefficient of every stratum is optimized by genetic algorithm based on monitoring data during reservoir filling.The saturated permeability coefficient of slidebody by back analysis is 4.89×10^-2 cm/s,which is consistent with field testing result（1.78×10^-2 cm/s to 3.2×10^-2 cm/s）;the saturated permeability coefficient of slipband by back analysis is 4.66×10^-5 cm/s,which is very larger than indoor testing result（2.74×10^-7 cm/s to 5.73×10^-7 cm/s）.The scale effect of soil sample is reflected by this difference.

关 键 词：非饱和渗流 渗透系数 BP网络 遗传算法 泄滩滑坡 

分 类 号：P641.2[天文地球—地质矿产勘探] TV139.14[天文地球—地质学]