一维积水入渗水分运移动态监测新技术  

An New Method for Monitoring Analysis of Water Flow in One-Dimensional Ponded Water Infiltration

作　　者：于光涛 张华[1] 倪明孚 黄亮 YU Guangtao;ZHANG Hua;NI Mingfu;HUANG Liang(National Field Observation&Research Station of Landslides in the Three Gorges Reservoir Area of Yangtze River,China Three Gorges Univ.,Yichang 443002,China;Guangdong Jinhuihua Group Co.,Ltd.,Jiangmen 529300,China)

机构地区：[1]三峡大学湖北长江三峡滑坡国家野外科学观测研究站,湖北宜昌443002 [2]广东金辉华集团有限公司,广东江门529300

出　　处：《三峡大学学报（自然科学版）》2021年第3期31-36,共6页Journal of China Three Gorges University：Natural Sciences

基　　金：湖北长江三峡滑坡国家野外科学观测研究站开放基金项目(2018KTL12)。

摘　　要：水在土壤中入渗时湿润锋前后含水量、吸力等物理量变化剧烈,精准监测土壤内部湿润锋动态变化比较困难.本文选用微型数字温湿度传感器(SHT30),利用湿度传感器对水分的高灵敏性,监测了一维土柱积水入渗时湿度剖面的动态变化,对比分析了湿润锋及水分运移过程.通过3种不同干密度土柱的一维积水入渗试验,在土柱中心位置不同高度处由上至下布设湿度传感器,外部布置相机拍摄土柱边界湿润锋推进过程,结合有限元数值模拟,揭示了土柱中水分入渗规律.结果表明:湿度传感器能及时准确捕捉吸湿路径下湿润锋;土柱的干密度越大,同一深度湿度骤升得越晚,表明入渗速率随干密度的增大而减小;对比外部拍摄的湿润锋和内部监测的湿润锋,发现拍摄边界湿润锋略晚于内部,随着土柱干密度增大,两者差距缩小;Shahabi渗透系数经验公式比Kozeny-Carman公式更接近实测饱和渗透系数,SEEP/W有限元模拟湿润锋推进过程与实测结果吻合良好.During the infiltration in soils,the physical properties such as water content and suction change sharply at the wetting front,which causes difficulties to accurately monitor the dynamic changes of the wetting front in the soil.In this paper,a mini digital temperature and humidity sensor(SHT30)was used to monitor the change of humidity profile during one-dimensional soil column water infiltration,and the wetting front and water flow process were compared and analyzed.One-dimensional ponded water infiltration experiments of three kinds of soil columns with different dry densities were conducted.The humidity sensors were inserted at different heights at the center of the soil columns from top to bottom.A digital camera was set up to record the advancing process of the wetting front at the boundary of the soil columns.The water infiltration processes were revealed by tests and simulated by finite element method.The results show that:the humidity sensor can timely and accurately capture the wetting front under the moisture absorption path;the greater the dry density of the soil column is,the later the humidity rises at the same depth,indicating that the infiltration rate decreases with the increase of dry density;it is found that the boundary wetting front is slightly later than the interior,and the gap between them decreases with the increase of the dry density of the soil column considering 50%humidity as the arrival time of the wetting front;the empirical formula of saturated permeability coefficient by Shahabi is closer to the measured saturated permeability coefficient than that of Kozeny-Carman formula.The simulation results of wetting front advancing by SEEP/W show good agreement with the measured results.

关 键 词：积水入渗 湿润锋 湿度传感器 水分运移 数值模拟 

分 类 号：TU43[建筑科学—岩土工程]