Water drainage and gas collection with geocomposites - Hydraulic software

Abstract

Geosynthetic materials and, more specifically, drainage geocomposites are now widely used for water drainage and gas collection in applications as varied as final landfill covers, leachate collection in landfill cells, sub-slab depressurization systems under buildings, groundwater drainage under embankments, etc. The design methods used are based on the in-plane flow capacity of the geocomposites, which is determined by laboratory tests performed on 250-300 mm long product specimens. Fluid is injected into the thickness of the product and the drainage capacity is interpolated for an actual length of several meters. This paper presents the development of hydraulic design software for multi-linear drainage geocomposites, based on laboratory characterizations of the geocomposite and then validated with full-scale tests. The software gives a 3D model of the hydraulic curves in the geocomposite depending on the application for which the geocomposite is used, and the fluid to be drained (water, landfill gas, methane, air, etc.).