非饱和低渗透黏土非线性渗流定律与固结  

Nonlinear flow law and consolidation in unsaturated low-permeability clays

作　　者：邓英尔[1] 黄润秋[1] 刘慈群[2] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059 [2]中国科学院渗流流体力学研究所,廊坊065000

出　　处：《水动力学研究与进展（A辑）》2009年第1期99-105,共7页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金资助项目(40202036,40572163);四川省青年科学基金资助项目(05ZQ026-043);四川省教育厅重点科技项目(2008);地质灾害防治与地质环境保护国家专业实验室基金资助项目(GZ2004-05);中国博士后科学基金资助项目(第35批)

摘　　要：该文分析了渗流实验结果,得出:非饱和低渗透黏土渗流遵循具起始水力梯度的非线性渗流定律。考虑到在非饱和黏土中气相在含水饱和度大于90%时不能独立运动,基于该非线性渗流定律,分别建立了非饱和黏土定流量单向非线性渗流、定压单向非线性渗流、定流量径向非线性渗流固结数学模型。以黏性边界层思想,构造出了上述数学模型解的结构,以积分方程法,导出了非饱和低渗透黏土非线性渗流平均质量守恒方程、活动边界运动方程、压力分布与平均固结度计算公式。进行了实例计算分析,结果表明:与线性渗流相比,非线性渗流使黏土层同一位置处的无量纲超孔隙水压力增大,使非饱和低渗透黏土固结活动边界运动速度减小、使定流量单向渗流平均固结度增大。该文结果可用于非饱和低渗透黏土地质工程与岩土工程等领域。达西渗流固结计算是具有起始水力梯度的非线性渗流固结计算的特例。Some results of experiments were analyzed and it is found that flow in unsaturated low-permeability clay follows a nonlinear flow law with initial hydraulic gradient. Based on the nonlinear flow law, mathematical models of nonlinear flow and consolidation in certain a direction with constant flow rate or pressure, and in the radius direction with constant flow rate were established considering a fact that a gas doesn＇t flow freely when water saturation is more than 90%. Constructions of solutions to the models were given by using an idea of viscous boundary layer. Equations of average mass conservation and moving boundary, and formulas of excess pore pressure distribution and average degree of consolidation for nonlinear flow in unsaturated low-permeability clay were derived. For example, results show that： the initial hydraulic gradient makes excess pore pressure of the same site of clay stratum increases, the velocity of moving boundary decreases, the average degree of consolidation increases under the condition of nonlinear flow in certain a direction with constant flow rate. The results can be used in geology engineering and geotechnical engineering of unsaturated low-permeability clay. Calculations of consolidation of Darcy flow are a special case of that of the nonlinear flow with initial hydraulic gradient.

关 键 词：非饱和低渗透黏土 起始水力梯度 非线性渗流定律 固结 平均固结度 活动边界 

分 类 号：O357[理学—流体力学]