Leakage through Liners under High Hydraulic Heads

The overall goal of this project is to contribute towards the use of geosynthetics in the design of dams and other hydraulic systems. More specifically, this project aims at quantifying the leakage through geomembrane and composite liners under conditions representative of dams. Although experimental validation of leakage equations has been conducted, the relatively small head (e.g., 0.3 m) allowed over liners for environmental applications has restricted such validation to a narrow range of governing variables. Instead, the use of geomembrane and composite liners for hydraulic systems such as dams involves heads several hundreds larger than those in environmental applications, as well as vertical or near-vertical liner orientations. Accordingly, experimental data is needed to refine the available leakage equations for use in the design of hydraulic systems. An experimental testing program involving quantification of leakage under high heads through geomembranes, soils, concrete and combinations of various other geosynthetics is under way at the University of Texas at Austin. The experimental setup, preliminary results and the scope of additional studies are presented in this paper.