复合土工膜渗透性能试验研究  

Experimental investigation of the permeability of composite geomembrane

作　　者：张光伟[1] 张虎元[1] 杨博[1] 

机构地区：[1]兰州大学西部灾害与环境力学教育部重点实验室,兰州730000

出　　处：《水文地质工程地质》2011年第5期58-62,共5页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金(50678075)

摘　　要：以高密度聚乙烯复合土工膜为试验材料,利用柔性壁渗透仪测定一定时间间隔通过复合土工膜的渗透量,通过计算求得复合土工膜的渗透系数,分析渗透系数随渗透压和渗透压应力路径的变化规律。利用扫描电子显微镜拍摄复合土工膜的照片,从微观结构上揭示了渗透系数变化的原因。试验结果表明:柔性壁渗透仪可以精确测定复合土工膜的渗透性能参数;复合土工膜在0.1MPa的有效应力作用下,渗透压从0.1MPa增大到0.6MPa的范围内,渗透系数有3种变化趋势,分别是渗透系数基本不变、渗透系数随渗透压的增大而增大和渗透系数随渗透压的增大而减小。复合土工膜物理性质的不均匀性和渗透通道的形态是影响防渗效果的主要因素。High density polyethylene composite geomembrane is used as a test material and the flexible wall permeameter is used to calculate the coefficient of the composite geomembrane.Changes in hydraulic coefficients with osmotic pressure and osmotic stress path are analysed.Scanning electron microscope photographs from microcosmic structure reveals the reason for the changes in hydraulic coefficients.The test results show that the flexible wall permeameter can accurately determine the geomembrane hydraulic parameters.When the composite geomembrane is functioned under the effective stress of 0.1 MPa,the osmotic pressure increases from 0.1 MPa to 0.6 MPa,causing 3 kinds of change trends of the hydraulic coefficient：（1） basically unchanged,（2） increase with the increasing osmotic pressure,and（3） decrease with the increasing osmotic pressure.The inhomogeneity of the physical properties of the composite geomembrane and penetration channel pattern are the main factors influencing the impervious effect.

关 键 词：柔性壁渗透仪 复合土工膜 渗透系数 渗透压 

分 类 号：P641.2[天文地球—地质矿产勘探] TV441[天文地球—地质学]