考虑变形效应的非饱和土相对渗透系数模型  

A RELATIVE HYDRAULIC CONDUCTIVITY MODEL FOR UNSATURATED DEFORMABLE SOILS

作　　者：胡冉[1,2] 陈益峰[1,2] 周创兵[1,2] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]武汉大学水工岩石力学教育部重点实验室,湖北武汉430072

出　　处：《岩石力学与工程学报》2013年第6期1279-1287,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2011CB013500);国家优秀青年科学基金项目(51222903);国家自然科学基金面上项目(51179136)

摘　　要：相对渗透系数是土体非饱和渗流分析的重要参数,Mualem统计模型在土体相对渗透系数预测中得到广泛应用。然而,Mualem统计模型假定土体具有刚性的孔隙结构,因而无法反映变形对非饱和渗透系数的影响。笔者最近提出的变形土土水特征曲线模型为基础,建立考虑变形效应的非饱和土相对渗透系数的修正Mualem统计模型。修正模型引入某一饱和度条件下被水充满的平均孔隙半径这一参量,来反映有效饱和度及土体变形过程中孔隙形态变化对其非饱和渗透特性的影响。采用4种不同类型土体的非饱和渗透试验数据对修正模型进行验证。结果表明,修正模型给出的相对渗透系数预测值与实测值的均根误差相比Mualem统计模型减小27%,说明修正模型对于变形条件下土体的相对渗透系数具有更强的预测能力。研究成果为非饱和土渗流规律以及水–力耦合数值模拟等研究提供了更为可靠的理论模型。The relative hydraulic conductivity is indispensable for the seepage flow analysis in unsaturated soils.The Mualem statistical model is widely used to determine this parameter.With the assumption of rigid pore structures,however,the Mualem model is not suitable for describing the relative hydraulic conductivity in deformable soils.On the basis of a newly developed soil-water characteristic curve model for deformable soils developed by the authors,a modified Mualem model was presented,in which the mean radius of pores completely filled by water in a given degree of saturation was adopted to account for the effects of water content and soil deformation on the unsaturated hydraulic conductivity.Experimental data of four types of soils were used to evaluate the modified model.Comparing to the original model,it is indicated that the root mean square error between the experimental measurements and model predictions was reduced by 27%.This more reliable theoretical model can be used for better understanding the seepage flow and coupled hydro-mechanical processes in unsaturated soils.

关 键 词：土力学 非饱和土 相对渗透系数 变形 Mualem统计模型 孔隙分布 

分 类 号：TU43[建筑科学—岩土工程]