Geophysical techniques for characterisation of municipal solid waste landfills

This paper presents the seismic site characterisation of Mavallipura landfill in Bengaluru, India using multichannel analysis of surface waves (MASW). The survey was performed at top level up to a height of 25 m. Up to 6 m it consisted of uncompacted waste. Also, the shear-wave velocity increased with depth from approximately 74 to 150 m/s. A series of one- and two-dimensional MASW surveys at various levels of the landfill was carried out to map the site fully. A new empirical correlation between standard penetration test corrected N values and shear-wave velocity was also developed. The MASW survey results and correlation with the conventional geotechnical investigation are presented in this paper. The results showed that the seismic waves can achieve changes in shear-wave velocity and Poisson's ratio to conclude the amount of degradation taking place at the landfill and thereby provide some knowledge with regards to the properties required for evaluating seismic stability.