项目名称： 黄土湿陷过程中临界浸润面的形成机理及深度数值模型

项目编号： No.41472267

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 井彦林

作者单位： 长安大学

项目金额： 90万元

中文摘要： 水浸入湿陷性黄土，在一定压力下发生湿陷，黄土结构被破坏，孔隙减小、渗透性减弱，使水的入渗能力衰减，已发生湿陷的土层起到了隔水层的作用；同时孔隙的减小使土中孔隙间液桥力增大，使得水的入渗进一步受阻，故在一定深度内水的渗透能力与渗透阻力会达到平衡，浸润面停止向深部推进，即浸润面深度存在一临界值，在该深度以下，土的含水率不会明显增大，不会发生湿陷。本项目运用黄土力学与渗流力学等多学科交叉方法，通过野外及室内试验手段，从机理上揭示湿陷过程中的入渗及浸润面发展规律与形面机理，通过室内试验及数值计算方法确定浸润面临界深度。这一研究对大厚度湿陷性黄土的地基处理深度选择，对农业、水利工程中的土壤入渗等均有积极意义。

中文关键词： 黄土湿陷；变渗透性；临界浸润面；数值模型

英文摘要： Water infiltrating into loess is the process that filtrating surface moves forward. Water infiltrates into the collapse loess and collapse occurs under certain pressure. When it happens, the structure of loess is broken, the gap reduces and permeability decreases, resulting in decline of water infiltrating capability.The air in aeration zone, which is below saturated zone, is leaked out hardly and compressed, so the air pressure increases and thereby the water infiltration is further impeded. Therefore, under a certain depth, water infiltrating capability and infiltrating resistance can reach a balance, the depth of infiltrating surface has a threshold limit value. Under this value, moisture content does't increases obviously and collapse does't occur any more.By applying seepage mechanics, loess mechanics and other intersecting sciences as well as utilizing outside and inside experimental methods, this research studies the change of physical property in seepage and collapse processes, analyzes permeability and change of infiltrating surface, as well as discussing laws in its occurance and development, and calculating critical depth of infiltrating surface.This research is significant for depth selection in the process of dealing with thick collapse loess foundations and soil infiltration in agriculture and hydro engineering.

英文关键词： loess collapsibility;variable seepage;critical infiltrates surface;numerical model