单向拉伸对土工织物反滤性能影响的试验研究

为研究单向拉伸对土工织物反滤性能的影响，选取两种条膜机织有纺织物和两种短纤针刺无纺织物，将不同拉应变下的织物与非连续级配土组成反滤系统，利用梯度比渗透仪测试系统反滤参数随拉应变的变化。根据反滤设计的透水、保土和防淤堵3个准则，分析拉应变对透水率、漏土量、梯度比等各参数的影响。试验结果表明：随着拉应变增加，有纺织物透水及防淤堵性能增强，保土性能减弱；无纺织物则相反，透水及防淤堵性能减弱，保土性能增强；同种土工织物厚度越大，拉应变对其反滤性能影响越大。

Influence of uniaxial tensile strain on filtration characteristics of geotextiles

Gradient ratio tests are carried out to study the influence of uniaxial tensile strain on the filtration characteristics of geotextiles. Four kinds of geotextiles (two needle-punched nonwoven and two slit-film woven) are employed in the tests. The filtration systems are composed of the geotextiles under designed uniaxial strains and gap-graded soils. The variations of the mean flow rate, the weight of soil passing through the geotextile and the gradient ratio with strains are analyzed based on the filtration criteria. The experimental results illustrate that the permeability and anti-clogging capabilities of woven geotextiles increase with the increase of the uniaxial tensile strain, but the retention capabilities decrease. The influence of tensile strain on nonwoven geotextiles is just the reverse. Moreover, the thicker the geotextiles are, the larger the influence of strain is.