Dimitrios Zekkos, Ph.D., P.E., M.ASCE; Mohammad Kabalan, EIT, A.M.ASCE; and Michael M. Flanagan, P.E., M.ASCE, are the recipients of the Collingwood Prize for their paper “Lessons Learned from Case Histories of Dynamic Compaction at Municipal Solid Waste Sites,” published in the May 2013 issue of ASCE’s Journal of Geotechnical and Geoenvironmental Engineering. The paper, whose findings are of immediate adaptability to professional practice, describes a compilation of investigations that contributes in a meaningful way to the advancement of engineering knowledge in geoenvironmental engineering. In the paper, a database of 56 test sites had been developed for the purpose of interpreting and analyzing the compiled data to develop key lessons learned on the performance of the use of dynamic compaction at municipal solid waste landfill sites. Analysis of the data indicated that the depth of improvement through the use of dynamic compaction is shallower than the depth of improvement typically observed in cohesionless soils. Vibrations induced by dynamic compaction are attenuated faster in municipal solid waste, which tend to have high organic content, and are more compressible than in inorganic, stiffer soils. These field observations are in agreement with laboratory experiments on municipal solid waste that indicate that the small-strain material damping of municipal solid waste is higher than that of inorganic soils. The study demonstrated that surface wave seismic methods provide a sound and practical approach to assessing the depth of improvement. Thus, the depth of improvement can be assessed reliably following the application of dynamic compaction at a municipal waste landfill site.
Trio of Civil Engineers Win ASCE’s Collingwood Prize
August 8, 2014