摘要
基于双重渗透介质模型,结合大孔隙优先流模拟试验,对比了非饱和渗流与非饱和优先流的计算结果,并分析了雨强、持时、大孔隙域渗透系数(Ksf)、两域交界面处水力传导系数(Ksa)、团粒中心至大孔隙边界距离(a)、大孔隙与整个土体体积之比(wf)等参数对优先流计算结果的影响规律。结果表明:1)双重渗透模型具有较好的计算精度,能反映非饱和优先流特性。2)非饱和优先流作用下边坡浅层湿润锋深度明显更大但浅表层基质域含水率更小,且相同位置的基质域含水率明显大于大孔隙域含水率。3)非饱和优先流模型得到的基质域湿润锋深度大于非饱和渗透模型计算值,但含水率呈相反趋势。4)增大Ksf、a、wf或减少Ksa,使两域间水分交换加快,靠近坡面处基质域体积含水率越大,湿润锋深度越小。研究成果可丰富降雨型滑坡渗流理论并支撑灾害防治。
Influence law of the factors（i.e.,rainfall intensity,duration time,permeability coefficient of macropore domain（Ksf）,the conductivity of the matrix-fracture interface（Ksa）,the equivalent diffusion distance between two domains（a）and the volumetric fraction of macropore domain（wf）,et.al）on the seepage mechanism of preferential flow were analyzed by unsaturated seepage model and dual permeability model.The results show that the double permeability model has high calculation accuracy and it can reflect the characteristics of unsaturated preferential flow.The depth of wetting front（water content of matrix domain）calculated by unsaturated preferential flow model is more（less）than that calculated by unsaturated seepage model.The water content in the matrix domain at the same location is more than that in the macropore domain since the permeability coefficient in the macropore domain is much larger than the permeability coefficient in the matrix domain.The depth of the wetting front in the matrix domain calculated by the unsaturated preferential flow model is more than that calculated by the unsaturated seepage model,but water content shows a reverse trend.With the increase of some parameters（i.e.,Ksf,a and wf）,the wetting front moves down,but the water exchange rate increases.And the water content of slope will decrease with the increase with Ksa.The research results can rich landslide theory induced by rainfall and support disaster prevention and control.
出处
《有色金属（矿山部分）》
2017年第6期71-77,共7页
NONFERROUS METALS(Mining Section）
基金
国家自然科学基金项目(41302215
41772297)
福建省自然科学基金项目(2014J01185)
关键词
强降雨
残积土
优先流
双重渗透模型
heavy rainfall
residual soil
preferential flow
dual-permeability model
