Influence of geosynthetic interface within a liner system in dynamic analyses of a landfill

Geosynthetic composites are extensively used in liner systems which are placed beneath the landfill to isolate waste material from the surrounding environment. However, geosynthetics can also be the weak interface, so analyses of seismic response and permanent deformation of landfill should be performed considering the influence of liner interface. This paper investigates the contributing role of the base liner on the seismic behavior of landfills. Based on the results of the site investigation, dynamic analyses of a landfill in Northern Italy were carried out with the finite difference computational platform FLAC-2D. The displacement of the geosynthetics resulting from the seismic loading was estimated along with the potentially induced seismic slip surface taking place at the interfaces. Results indicate that the geosynthetic liner system affects the dynamic response of landfill and that the seismic displacements on the geosynthetics should not be neglected. This paper also discusses results and implications on seismic design of landfills to ensure the integrity of the liner systems as well as the stability of the waste landfill.