FIELD EVALUATION OF GEOSYNTHETIC CUSHIONS FOR GEOMEMBRANE PROTECTION

摘要

Recent changes in solid waste landfill designs have necessitated the use of a 60-mil high-density polyethylene (HDPE) to serve as a "leak" protector to prevent leachate from contaminating groundwater supplies. For this HDPE liner to function properly, minimal head is allowed to act upon it. Therefore, a leachate collection and removal (LCR) system must be constructed. Proper drainage for the LCR system requires a pervious material such as crushed stone. However, using an angular tough material such as crushed stone on top of a "plastic" liner raises many concerns of liner punctures. Many landfill design engineers will not allow the use of crushed stone without a protective cushion separating the stone from the liner. Due to a lack of knowledge/research, many designers specify extremely heavy-weighted fabrics. These heavy fabrics/cushions, thought necessary to prevent punctures, are sometimes not economical to use. This paper reports on the first large scale, field-testing project that evaluates the proper weighted cushion necessary to protect HDPE liners from punctures related to stone drainage layers.