Assessment of the Landfill Barrier System through Numerical Analysis: Rehabilitation and Expansion of Belgrade Landfill Case Study

There are still many unmanaged landfills around the world that pose significant potential environmental problems. One of the largest unmanaged landfills in Europe, which has been used for more than 40 years to deposit waste from Serbia’s capital, Belgrade, is the Vinča landfill. A revitalization and extension of this landfill was proposed that would allow its sustainable operation in the future. The revitalization project considered building a capping layer on the surface of the current landfill, which will close it and which will serve as a liner on the bottom of the new landfill. The use of a composite system including a HDPE geomembrane is considered in the project. New landfill settlements were predicted using the FEM method utilizing a Hardening-soil constitutive model for subgrade. Both immediate settlements of subgrade caused by waste deposition and primary consolidation settlement were calculated. The results show that a substantial increase in the settlement of the geomembrane subgrade can be expected during the primary consolidation period, due to the high rate of filling compared to the permeability of the subgrade. The total settlement of the new landfill in its crown is expected to be between 2.73 and 4.52 m. The axial force in the geomembrane will not exceed the tensile strength of the membrane at any time during or after the new landfill operation.