Engineered Impact Compaction Of Un-Engineered Fills

Un-engineered fill sites are often characterised with variable and excessive settlement potential. Impact Compaction has been used extensively on sites of this nature as an economic alternative to the removal and replacement of the in situ fills as engineered fills. Impact compaction has in the past been applied simply with a pre-determined number of passes or a number of passes determined on site based on the average compaction settlement over large areas and visual observation by a geotechnical engineer. This technique provides only partial “engineered” fill, as the possibility of un- identified sub-surface deleterious material still presents some risk of adverse foundation performance which requires the use of conservative design parameters.

Innovative technologies have been developed that enable “Engineered” Impact Compacted fills that significantly reduce the risks associated with unidentified sub-surface deleterious material and spatial sub-grade variation. Case studies are presented where the reworking of un-engineered fills with “Engineered” impact compaction using innovative continuous impact response technology (CIR) and continuous induced settlement technology (CIS) allowed the use of slab–on-ground construction and upper level footings with more realistic design parameters.