Wind-induced uplift of exposed geomembrane covers: A proposed revision to conventional design approaches

摘要

Conventional approach for exposed geomembrane design assumes that the geomembrane is subjected to an uplift pressure induced by wind above the geomembrane, and the pressure below the geomembrane is kept constant at atmospheric pressure by default. In reality, the exposed geomembrane is typically anchored into subgrade, which limits the exchange of air above and below the geomembrane. Therefore, when the geomembrane is being uplifted, suction will be generated temporarily below the geomembrane. This temporary suction provides significant resistance to uplift during short-duration wind gust. This paper recommended revisions to the current design approach. An average wind velocity within a selected period, instead of the 3-s gust speed, is recommended to be used for design. This period can be selected based on evaluation of how fast air can enter the voids below the geomembrane.