Research Supervisor: S. Thevanayagam, Associate Professor and MCEER Director of Education

Remediation of liquefiable loose granular sand and non-plastic silty sand deposits during seismic loading is a major problem in geotechnical earthquake engineering. Sand deposits densified by dynamic compaction (DC) are more resistant to liquefaction, and have performed well during earthquakes. Silty sand deposits may also be densified using DC supplemented with pre-installed wick drains. Current design methods of DC depend mainly on expensive field trials. This paper presents a set of simplified design charts and procedures to determine the densification achievable during ground improvement of sands and non-plastic silty sands using DC supplemented with pre-installed wick drains. The methodology is based on a model for performance of soil deposits during dynamic compaction using energy principles governing soil liquefaction and soil densification by consolidation. Design example is also presented