MASW survey to estimate the unit weight of municipal solid waste at a lanalail in Brazil

Non-invasive and non-destructive geophysical methods, such as the multichannel analysis of surface waves (MASW), can effectively provide useful information about the mechanical properties (stiffness and unit weight) of municipal solid waste (MSW), during and after landfill operation, for environmental monitoring and engineering analysis. This paper aims to address the results of a seismic survey performed at a sanitary landfill located 40 km north of Rio de Janeiro, Brazil, to image shear-wave velocity profiles to a depth of about 20 m. Seismic data were collected using the MASW method, performing an active and passive combined survey. Shear-wave velocities were used to compute the in situ unit weight distribution of MSW according to the empirical model proposed by Zekkos et al. Results indicated a two-layer model in which the bottom high-velocity layer is stiffer and denser than the top low-velocity layer. Despite the fact that the unit weight appeared to be underestimated for the upper low-velocity layer, model predictions may be graded qualitatively as excellent and potentially more accurate with well-calibrated parameters.