Performance evaluation of alternative drainage material for landfill cover systems in combination with geosynthetics

Indian Institute of Technology Roorkee, Civil Department, 247667 Roorkee, India

^* Corresponding author: anumita.mishra@ce.iitr.ac.in

Abstract

The pursuit of sustainable development has prompted increased utilization of alternative materials in landfill cover systems. Despite evaluating these materials for hydraulic and strength properties, their performance with geosynthetics remains inadequately explored. This study focuses on investigating the use of recycled asphalt pavement (RAP) as an alternative drainage material and determining the interface friction angle between the drainage layer and the geomembrane through large-scale direct shear tests. Further, a numerical model of a municipal solid waste landfill in Italy was developed using Finite Element Method (FEM) software. Model validation was achieved by applying analytical two-wedge theory of veneer shear failure in layered strata. The study demonstrates a superior performance of RAP aggregates as drainage layer materials as compared to natural aggregates. It also emphasizes the importance of site-specific parameter determination and precise interface property characterization. Limitations of use of commercial software in identification of weak interfaces has also been highlighted.