Chung Moonkyung, Seo Min Woo, Kim Kang Suk, Park Jun Boum
Geotechnical Engineering Department, Korea Institute of Construction Technology, Gyeonggi-Do, Korea.
Waste Manag Res. 2006 Jun;24(3):250-9. doi: 10.1177/0734242X06063055.
Geosynthetic liner systems are generally installed in landfill sites to prevent toxic leachate from escaping into the adjoining environment by utilizing their impervious characteristics. Therefore, it is important to protect the geomembrane from being damaged or destroyed during all phases of landfilling, namely landfill construction, waste tipping and landfill closure. This paper presents firstly the observed performance of a geomembrane liner from a landfill site where the geomembrane liner was installed on the slopes of a Korean landfill; and secondly the results of an inclined board laboratory test. Two types of experiments were conducted to identify the protecting effect of the overlaying geosynthetic on the geomembrane liners. At a testing landfill site, the slope consisted of three different sub-inclines and two 2-m-wide intermediate levels. The sub-inclines were each 8 m in vertical height and their angle of inclination was 1: 1.5 (vertical: horizontal). The reported observations were made for a time period of approximately 1 year, until the landfill was filled with wastes to the top of the uppermost slope. In addition, inclined board laboratory tests were carried out. During the inclined board test, a base table is inclined slowly and steadily until the block located on the base table starts to slide, when the tension and displacements of two geosynthetics, namely the geomembrane liner and protecting geotextile, are measured. In conclusion, test results showed that the down-drag force generated by waste accumulation and sliding of upper material was to a large extent dissipated through the elongation of the protecting geosynthetic overlying the geomembrane and thus was not transferred to the geomembrane. Unless the protecting geosynthetic undergoes structural failure, this stress relaxation phenomenon continues to occur so that the magnitude of tensile force to be applied on the geomembrane remains marginal.
土工合成材料衬垫系统通常安装在垃圾填埋场，利用其防渗特性防止有毒渗滤液泄漏到周边环境中。因此，在填埋的各个阶段，即填埋场建设、垃圾倾倒和填埋场关闭期间，保护土工膜不被损坏或破坏非常重要。本文首先介绍了一个垃圾填埋场土工膜衬垫的观测性能，该土工膜衬垫安装在韩国一个垃圾填埋场的斜坡上；其次介绍了倾斜板实验室测试的结果。进行了两种类型的实验，以确定覆盖的土工合成材料对土工膜衬垫的保护作用。在一个测试垃圾填埋场，斜坡由三个不同的子斜坡和两个2米宽的中间层组成。每个子斜坡的垂直高度为8米，倾斜角度为1:1.5（垂直：水平）。报告的观测持续了大约1年时间，直到垃圾填埋场的垃圾填满到最上面斜坡的顶部。此外，还进行了倾斜板实验室测试。在倾斜板测试中，基台缓慢而稳定地倾斜，直到位于基台上的块体开始滑动，此时测量两种土工合成材料，即土工膜衬垫和保护土工织物的拉力和位移。总之，测试结果表明，垃圾堆积和上层材料滑动产生的下拉力在很大程度上通过覆盖在土工膜上的保护土工合成材料的伸长而消散，因此没有传递到土工膜上。除非保护土工合成材料发生结构破坏，这种应力松弛现象会持续发生，从而施加在土工膜上的拉力大小仍然很小。
