State of the art and durability insights regarding the use of geosynthetics for lining in hydraulic and environmental applications
Etat de l'art et point sur la durabilité concernant l'utilisation des géosynthétiques pour l'étanchéité de ouvrages hydrauliques
Résumé
Geosynthetics have been widely used in the past thirty years in a number of hydraulic and environmental applications. The aim of this paper is first of all to illustrate the use of geosynthetics in some hydraulic and environmental applications, i.e. canals and dikes, ponds, covers for potable water impoundments, mountain reservoirs and ponds for environmental protection. A brief insight where documents exist on regulations or guides of recommendations for the use of geosynthetics in such applications is given. Then a discussion of the evaluation of the performance of liner systems at field scale is presented, with a brief overview of electrical leak detection systems and optic fiber measurement. The durability of bituminous, polyvinyl chloride and polypropylene geomembranes in hydraulic applications is then discussed based on field experience and some laboratory quantification of the flow of water through geomembranes. Field data related to the performance of geosynthetic clay liners (GCLs) in hydraulic applications are also presented based on a literature review. The factors impacting the performance of GCLs are discussed. An insight is also given in the factors impacting the performance of GCLs in landfill covers and a synthesis of common features and recommendations for those various applications is given. Finally, a discussion on the methodologies that can be used to evaluate the adequation of the bentonite in a GCL for a given application in order to ensure the best possible performance of the GCL is presented, together with preliminary recommendations.