摘要
非饱和土渗透系数是随体积含水量变化的一个复杂变量,难于通过试验直接获取,实际工程中主要采用经验公式,难免与实际存在不符.提出了基于一维垂直渗流控制方程差分求解及非饱和渗透性试验联合确定非饱和土渗透系数的新方法.首先利用有限差分法对一维垂直渗流控制方程进行离散,获得基于差分格式的非饱和土渗透系数表达式;然后通过试验获得土样饱和渗透系数、土水特征曲线以及不同位置处体积含水量随时间变化的关系曲线,通过Matlab编程将以上各参数代入离散后的差分格式,即可得到非饱和土渗透系数随含水量的变化值.将该方法得到的渗透系数与VG模型求出的渗透系数进行对比,两者误差较小,说明本文提出的确定非饱和土渗透系数的新方法具有一定的可靠性.
The permeability coefficient of unsaturated soil is a complicated variable with the change of volumetric water content,which is difficult to obtain directly through experiments.In practical engineering,the empirical formulas are mainly adopted,which are inevitably inconsistent with the reality.In light of above-mentined issues,a new method based on differential solution of seepage control equation and unsaturated permeability test to determine the permeability coefficient of unsaturated soil.Firstly,the finite difference method is used to discretize the one-dimensional vertical seepage control equation.Then the soil saturated permeability coefficient,soil water characteristic curve and volumetric water content at different positions and times are obtained by experiments.The above parameters are substituted into the discrete difference format by Matlab programming to obtain the unsaturated soil permeability coefficient.The permeability coefficient obtained by this method is compared with that of VG model;and the error of the two methods is relatively small,so as to indicate that the new method proposed to determine the permeability coefficient of unsaturated soil has certain reliability.
作者
江明
王世梅
张兰慧
刘凡
Jiang Ming;Wang Shimei;Zhang Lanhui;Liu Fan(College of Civil Engineering&Architecture,China Three Gorges Univ.,Yichang 443002,China)
出处
《三峡大学学报（自然科学版）》
CAS
北大核心
2019年第6期59-64,共6页
Journal of China Three Gorges University：Natural Sciences
基金
国家自然科学基金项目(41372359)
中国地质调查局项目(DD20190716)
中国地质调查局项目(DD20190638)
关键词
非饱和土
有限差分法
一维渗流
渗透系数
VG模型
unsaturated soil
finite difference method
one dimensional seepage flow
permeability coefficient
VG model
