表征雨水在土体裂隙内优势入渗过程的解析模型  

Analytical model for preferential infiltration into cracks in soils

作　　者：张昭[1] 祝良玉 李光耀 袁昊钰 高帅东 韩华强[2] 刘奉银[1] 齐吉琳 ZHANG Zhao;ZHU Liangyu;LI Guangyao;YUAN Haoyu;GAO Shuaidong;HAN Huaqiang;LIU Fengyin;QI Jilin(Institute of Geotechnical Engineering,Xi'an University of Technology,Xi'an 710048,China;Nanjing Hydraulic Research Institute,Nanjing 210024,China;College of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China)

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048 [2]南京水利科学研究院,江苏南京210024 [3]北京建筑大学土木与交通工程学院,北京100044

出　　处：《岩土工程学报》2023年第9期1831-1840,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(42372336,41877278);国家留学基金项目(201908610043);陕西省教育厅重点实验室科研计划项目(18JS071);陕西省科技创新团队项目(2022TD-01)。

摘　　要：解释雨水入渗裂隙土体时出现优势流现象的关键,在于定量描述雨水优势入渗土体裂隙的过程。为此,先基于Green-Ampt入渗模型构建表征雨水在团粒-裂隙双区域运动特征的解析模型。其次,引入无量纲参数对解析模型进行概化,使之可预测在降雨强度不变时的优势入渗量与湿润锋深度,描述雨水入渗分区随时间的变化过程。模型的计算结果表明:雨水入渗分区在团粒表面出现积水与裂隙被水充满时会发生变化;优势入渗量所占比例随降雨强度和裂隙体积均呈单调递增趋势;裂隙内的湿润锋深度随其体积呈单调递减趋势。最后,对比分析解析模型与基于Richards方程的HYDRUS-1D数值模拟对雨水优势入渗3种含裂隙土的计算结果可知:解析模型与HYDRUS-1D的优势入渗量计算曲线趋势较为吻合,为定量描述雨水在土体裂隙内的优势入渗特征提供了一条新途径。Cracks induce preferential flows in many soils,creating the need for analytical solutions to describe the preferential infiltration processes.In response,the Green–Ampt infiltration model is first applied within the aggregate-crack dual-domain model to distinguish water movement through aggregate versus through crack.In addition,using a set of non-dimensional parameters to generalize the analytical model,the developed model can estimate the infiltration and depth of wetting due to the preferential flows during the constant-intensity rain.The results show that the infiltration partitioning varies with time,with flow regimes changing at the time of ponding of the aggregate and again at the time when the crack abounds with water.The fraction of preferential infiltration increases monotonically as a function of the rainfall intensity and the relative volume of the crack domain.Conversely,the wetting depth in the crack domain decreases monotonically as a function of the relative volume of the crack.Finally,the proposed analytical model is compared with HYDRUS-1D numerical simulations based on the Richards equation for three soils with cracks.The analytical model closely approximates the numerical results,so as to provide a novel insight into the preferential infiltration dynamics during rainfall events for the cracks in soils.

关 键 词：团粒 裂隙 优势入渗 双区域模型 

分 类 号：TU431[建筑科学—岩土工程]