We worked on a 14-story residential tower in Southbank where the fill layer was over 8 meters deep. The old river deposits made conventional shallow foundations impossible. Dynamic compaction design was the only method that could densify that heterogeneous fill to a consistent bearing capacity. We specified a 20-tonne tamper dropping from 25 meters on a 4-meter grid. Before the drop program, we ran a [MASW survey](/masw-vs30/) to map the loose zones across the site. That survey saved weeks of trial drops. The final compaction pass achieved an average blow count of 12 in the top 6 meters. The tower now sits on a stiffened raft designed for 200 kPa.
The Menard method predicted 8 meters of improvement. Actual results matched within 6% on that Altona site.