Exposed Geomembrane Cover Design: A Simplified Design Approach

There have been several exposed geomembrane cover (EGC) applications permitted as long-term interim cover systems for landfills since 1992. The first EGC as final closure was approved by State of Georgia in 2009. This EGC utilizes a 1.5-mm (60-mil) reinforced polypropylene geomembrane adhered with flexible photovoltaic (PV) cells to generate electricity. This paper presents a simplified design approach used to improve previous EGC designs by incorporating a modified anchor trench configuration to more effectively address wind uplift and ease the installation process. Calculations for the anchor trench pullout due to the modified anchor trench configuration are discussed and the wind suction coefficients, previously published using models tested in wind tunnels, are modified by considering suction forces generated under the EGC and other similar designs that have taken place over the last thirty years. The paper concludes with a case study of a final EGC design which incorporates PV cells to generate revenue during the post closure period. The case study demonstrates the design simplifications, determination of wind uplift forces, design considerations for anchor trench pullout and anchor trench dimensions.