Heat Mitigation in Geosynthetic Composite Liners

Professor Abdelmalek Bouazza, Ph.D.Professor of Civil and Environmental EngineeringMonash University

Friday, March 17, 2017

Abstract: Composite liners comprised of a geomembrane overlying either a geosynthetic clay liner (GCL) or a mineral (low permeability soil) liner are routinely used as engineered hydraulic barriers in waste containment facilities, including hazardous and municipal solid waste landfills, tailings dams, liquid waste storage ponds, cooling ponds for power plants, and brine ponds for geothermal energy production facilities. The diversified nature of the different wastes (often having extreme chemistries) in these facilities pose challenges regarding not only the hydraulic performance of these composite liners but also their longevity. Elevated temperatures are often present in these facilities and s factor can impact both the performance and the durability of these composite lining system.

Elevated temperatures in the waste give rise to temperature gradients across the liner system and into the subsoil. These gradients in turn can lead to drying and/or heat induced desiccation cracking in the GCL or mineral liner layer of the system. This condition presents practical challenges as very often the hydraulic performance of liners exposed to elevated temperatures is not anticipated in the design process. The presentation will examine the hydro-thermal behavior of lining systems configurations that are frequently encountered in practice. It will also explore means of protecting both a GCL and the subgrade against possible drying and/or heat induced desiccation.

Bio: Abdelmalek Bouazza, Ph.D., received his undergraduate degree in civil engineering in 1984 from Ecole Polytechnique d’Alger in Algeria and his PhD in Civil Engineering, from University of Glasgow, United Kingdom in 1990. He currently serves as a Professor of Civil and Environmental Engineering specializing in geotechnical engineering at Monash University in Melbourne, Australia. He is widely recognized for his work on the application of geosynthetics for waste containment and other civil engineering applications. He currently chairs the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) Technical Committee 215 on Environmental Geotechnics and serves a Secretary of ISSMGE TC308 on Energy Geotechnics.