Seismic Imaging of a Leachate-Recirculation Landfill: Spatial Changes in Dynamic Properties of Municipal Solid Waste

AbstractLeachate-recirculation landfills enhance waste degradation through percolation of leachate inside the waste mass. In situ monitoring of moisture distribution and changes in mechanical properties (stiffness) of municipal solid waste (MSW) is needed to optimize the safe and effective operation of these types of landfills. Geophysical methods, such as electrical-resistivity tomography, have effectively monitored moisture distribution during and after leachate injection. This study investigates seismic surveys to capture the changes in mechanical properties [shear modulus (via shear-wave velocity) and Poisson’s ratio] of MSW to infer the extent of degradation and provide dynamic properties needed for seismic stability evaluation. To achieve this goal, a series of seismic surveys were performed at the Veolia ES Orchard Hills landfill, 15 km south of Rockford, Illinois, to image seismic velocity structure and the Poisson’s ratio of a recirculation cell, compared with an adjacent newer landfill cell with...