土工膜/无纺土工织物界面强度形成机理研究

Research on Mechanism of Geomembrane/Geotextile Interface Strength

为研究填埋场衬垫系统中土工膜/无纺土工织物界面强度受界面接触状态的影响,将界面接触状态作为单一变量进行直剪试验,排除法向应力等其他因素对界面强度的影响,得到土工膜/无纺土工织物界面接触状态随法向应力的变化。通过对预压直剪试验和常规直剪试验结果的比较找出土工膜/无纺土工织物界面接触状态的变化对界面强度的影响。发现界面接触状态中裹覆纤维比和裹覆纤维密度这两个参数是影响界面峰值强度的主要因素,并建立界面峰值强度预压前后的增量与裹覆纤维比和裹覆纤维密度的关系式。即使法向应力不变,土工膜/无纺土工织物界面接触状态改变也能使界面峰值强度发生变化。

In order to study the effect of the interface contact status on the geomembrane/geotextile interface strength in landfill site ,and taking the interface contact status as the only variable ,the direct shear tests were carried out by exclud-ing the effects of other factors so as to obtain the changes of the geomembrane/geotextile interface contact status with nor-mal stress .Through comparing with the results of preloading direct-shear test and normal shear test ,the effects of the changes of the geomembrane/geotextile interface contact status on the interface strength were identified .It is found that the wrapping fiber ratio and wrapping fiber density are the major influencing factors on the interface strength peak ,and based on this ,the connection formula between the increment of the interface strength peak before and after preloading and the wrapping fiber ratio together with the wrapping fiber density is established .The research results show that with the constant normal stress ,the changes of the geomembrane/geotextile interface contact status could result in the changes of the interface streugth peak .