Laboratorial Prototype for Detection of Defects on Geomembranes - The Geophysical Approach

Abstract

Although there are some test methods do detect and locate defects in geomembrane liners after the placement of the primary leachate collection system, namely the soil-covered geomembrane method (mobile probe) and the grid method (permanent), the existing methods present some disadvantages. They are labor and time consuming and, so, very expensive. These conditions lead us to the development of a quick and low-cost, but also accurate, test prototype to check the geomembranes integrity after the placement of the granular layer. The methodology consists in the development of a prototype combining the mobile probe method with the multicables resistivity equipments presently used for geophysical surveys. This prototype is endowed with ways that allow to the semi-automatic data acquisition (detection location of the defects) and its processing in real time. The functionality of the prototype is presently being verified in a pilot plant, at one of ISEL’s (Instituto Superior de Engenharia de Lisboa) laboratory. The experimental work under way includes different types of lining systems and defects. A bigger scale pilot plant is being constructed at LNEC’s (Laboratório Nacional de Engenharia Civil) campus, to verify, at real scale, its functionality. Afterwards, the prototype will be checked in situ, at a true landfill.