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

Abstract

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.

An overview of in situ testing and geophysical methods to investigate municipal solid waste landfills

“…Other authors calculated γ from V s using Eq. 1 (Cirone and Park 2020 ) and the correlation developed by Choudhury and Savoikar ( 2009 ) in Eq. 7 (Konstantaki et al 2016 ; Aranda et al 2019 ): …”

“…Some authors reported increasing V s with depth, suggesting a two-layer division of the waste body (Abreu et al 2016 ; Castelli and Lentini 2017 ; Castelli et al 2017 ; Cirone and Park 2020 ). Higher average velocities in the bottom layer were associated with the increased unit weight ( γ ) of old and deep MSW due to mechanical compression and changes in particle size distribution, mass, and volume during biodegradation.…”