降雨条件下残积土的优先渗流机理分析  

Analysis on preferential seepage mechanism of residual soil with macropore under rainfall

作　　者：詹小军 李洪艺 林登辉[2] 傅东阳[2] 

机构地区：[1]国土资源部丘陵山地地质灾害防治重点实验室,福建福州350002 [2]福州大学土木工程学院,福建福州350108 [3]广东省惠州市惠阳区住房和城乡规划建设局规划建设管理技术中心,广东惠州516211

出　　处：《广西大学学报（自然科学版）》2018年第1期261-268,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：福建省自然科学基金资助项目(2014J01185);国土资源部丘陵山地地质灾害防治重点实验室(福建省地质灾害重点实验室)开放基金资助(FJKLGH2017K003)

摘　　要：为揭示强降雨条件下残积土的优先流水分运移特性,基于双重孔隙模型,采用有限差分技术编制计算程序,对考虑与不考虑大孔隙的土体模型入渗进行比较,并对降雨强度、持时、基质域与大孔隙域间的水分传导系数(Ksa)等对水分非平衡迁移特性进行分析。结果表明,相同降雨条件下,考虑大孔隙条件下土体基质域湿润峰深度约为不考虑大孔隙条件下湿润峰深度的3倍,且同一湿润峰位置处的含水率较大。随着雨强和持时的增加,水流通过大孔隙入渗导致湿润峰深度快速增加,两域水分交换深度逐渐增大,但其峰值减小。增大Ksa值,土体基质域湿润峰深度逐渐增大,而大孔隙域湿润峰深度逐渐减小。In order to reveal characteristics of preferential water flow under heavy rainfall,based on dual porosity model,the permeabilities of soil models with and without consideration of macropore were compared,and influence of some factors on seepage mechanism of non-equilibrium flow was analyzed. The results show that the depth of wetting front（water content of matrix domain）calculated by unsaturated preferential flow model is about 3 times of that calculated by unsaturated seepage model,and that the moisture content at the same wetting front is larger. Depth of water exchange and wetting front will increase with the increase of rainfall intensity and duration time but peak of depth of water exchange will decrease. The depth of wetting front of soil matrix domainincreases gradually while the depth of wetting front of macropore domain decreases with the increase of K（sa）.

关 键 词：残积土 优先流 大孔隙 双重孔隙模型 有限差分 

分 类 号：TU4[建筑科学—土工工程]