Seismic in-Soil Isolation of Solid Waste Landfill Using Geosynthetic Liners: Shaking Table Modeling of Tehran Landfill

Seismic loads may damage municipal solid waste (MSW) landfills through the relative movements within the landfill system. These movements can disrupt performance of drainage and gas collection systems, thereby resulting in environmental pollution. The smooth synthetic materials might be placed beneath the structures to provide seismic protection by absorbing the imparted energy of earthquakes through the sliding mechanism. It has been found that a high strength geomembrane placed over the other smooth and lubricated geomembrane sheets constitutes an efficient seismic liner. In the present study, experimental investigations were conducted to evaluate role of in-soil base isolation on seismic response of the Tehran MSW landfill. Results of geophysical and geotechnical investigations in the landfill site are presented in detail. Shaking table tests were conducted on the MSW embankment isolated by semi-elliptic shaped liners and subjected to harmonic sinusoidal base excitations. The results for the isolated and non-isolated cases are compared in terms of permanent displacement and seismic response. It has been observed that at all elevations the spectral accelerations within the waste decreased by base isolation, especially for the more intense excitations. Results of the present study demonstrate a suitable application of geosynthetic liners for seismic retrofitting of landfills.