Wind Tunnel Study and Uplift Analysis of Geosynthetic Covers

Geosynthetic covers, including the exposed geomembrane cover and engineered turf cover, have been used as alternatives to conventional soil-geosynthetic covers for closure of landfills and other waste containment facilities. Because the geomembrane component in geosynthetic covers is not overburdened with a soil layer, uplift of geomembrane due to wind loads is of a concern in the design and construction of such covers. A wind tunnel study was performed to evaluate performance of an exposed geomembrane cover and the ClosureTurf engineered turf cover under wind loads on small-scale test models that were built to simulate a landfill cross section. The wind tunnel test results are presented in the form of dimensionless wind pressure coefficients. The wind-induced uplift pressure is found to be affected by the surface roughness of the cover and the slope ratio. The measured maximum uplift pressure coefficient values for the ClosureTurf engineered turf cover are approximately 30% of those for a smooth exposed geomembrane cover, demonstrating significant improvement of wind uplift resistance of the engineered turf cover. An example calculation of the maximum wind uplift pressure on the engineered turf cover is presented.