岩土二元介质坡地非饱和渗流特征试验研究  

Unsaturated seepage characteristics in the slope characterized by a weathered rock-soil dual entity

作　　者：曹建生[1] 张万军[1] 刘昌明[1] 杨永辉[1] 

机构地区：[1]中国科学院遗传与发育生物学研究所农业资源研究中心,石家庄050021

出　　处：《农业工程学报》2007年第8期9-15,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家863计划(2006AA100204);中国科学院重大方向性项目(KSCX2 - YW- N- 017 - 001);河北省科技攻关项目(06230201D);研究所创新项目"山地水环境与农业可持续发展"资助

摘　　要：为了研究岩土特性对坡地降水转化及再分布的影响,利用自行设计的大型渗透仪,对扰动组合岩土体天然降雨条件下的非饱和渗流特征进行了试验研究。结果表明:在进行岩土非饱和渗流计算时,岩体层应依据双重介质模型,并充分考虑岩块与裂隙填充物的不同,按照两者的体积含水率和体积大小分别计算其水分含量并求和得到岩体层的水分含量;下部相对弱透水层与相对高含水层的存在是壤中流发生的主要条件,在岩土水分含量较高的情况下,当降雨入渗到土壤与岩石交界面后,沿岩土界面产生侧向优先流,该优先流在水平和垂直方向交互作用引起水分在岩体裂隙中快速入渗;裂隙岩体的风化程度对非饱和渗流具有重要影响,在强风化的裂隙岩体中,水分不仅在裂隙网络中运动,同时由于岩块的风化分异,岩块的表层也参与了部分水分运动。To study the effect of soil-rock＇s characteristics on the transformation and redistribution of precipitation, the characteristics of unsaturated seepage in disturbed rock-soil entity were measured using a large manmade lysimeter during a rainfall event. Results indicate that the dual-media model should be adopted to calculate the amount of unsaturated seepage in rock layer, considering the difference of rock and fissure filler, and the rock and filler are the two medias. Water amount is calculated separately according to the volumetric content of water in various media and the volume of corresponding media, and the sum is the total water amount in lower rock layer. Subsurface flow only occurs as there is aquitard and a relative high aquifer at the lower part. Lateral preferential flow emergences as rainfall in the high aquifer infiltrates into the boundary of soil and rock, and then water moves quickly along the fissures of rocks in vertical and horizontal dimensions. Unsaturated seepage in rock layer is strongly affected by the weathering intensity of the fissured rock. If rock is highly weathered, a certain amount of water also moves in the surface layer of the rock except for in the fissures.

关 键 词：模拟试验 壤中流 岩土二元介质 非饱和渗流 渗透仪 

分 类 号：P641.135[天文地球—地质矿产勘探] O357.3[天文地球—地质学]