填埋场斜坡上土工膜受力特性的离心模型试验研究

由于垃圾土沉降大,斜坡上土工膜易受到较大下拽力而破损,影响衬垫系统防渗功能。通过离心模型试验对填埋场斜坡上土工膜在垃圾土重力和沉降作用下的拉力和应变进行了研究,并通过FLAC数值对比分析,可获得如下结论：试验采用的模型垃圾土能很好地模拟现场垃圾土,模型土最大沉降量可达土层厚度的20%；土工膜存在中性点,以中性点为界土工膜可分为受拉区和受压区,中性点的位置与坡度和沉降有关,从坡顶到中性点拉应变逐渐变小,从中性点到坡脚压应变先增大后减小；坡度和沉降是影响土工膜拉力发展的重要因素,坡度或沉降越大,拉力越大,沉降是通过改变界面强度的发挥程度来影响土工膜拉力的发展；当采用单糙面土工膜（上光下糙）时,外部作用力很难向土工膜下界面传递,土工膜锚固端拉力几乎为零。

Centrifugal model tests on stress characteristics of geomembranes placed on landfill slopes

The geomembranes placed on landfill slopes may suffer great tension and be damaged as a result of large settlement of waste. The tension and strain of geomembranes on the landfill slopes are studied using centrifugal model tests. Through FLAC simulation, it can be concluded that: (1) the model waste used in the test has good similarity with the prototype one, and the maximum settlement of model waste can reach 20%; (2) the geomembrane has tension and compression zones which are separated by the neutral point, and the position of the neutral point is affected by gradient and settlement. The tensile strain becomes smaller from the top of the slope to the neutral point, while the compressive strain decreases after increasing from the neutral point to the foot of the slope; and (3) the gradient and waste settlement are important factors to affect the development of tension, and the settlement affects tension by changing the mobilized interface strength. The tension is very small when the upside of geomembranes is smooth while the downside is rough because the external force is difficult to pass to the internal.