Located at Swan Island on the Willamette River, the new Daimler Building is subject to lateral spread and liquefaction hazards. Poorly compacted undocumented fill soils at the site pose bearing capacity and static settlement issues for the new building. AGI worked with the owner to design and install a Deep Soil Mixing Buttress to reduce the lateral spread hazard and Aggregate Pier (AP) ground improvement to support the buildings shallow foundation to increase bearing capacity and reduce static settlement. The DSM buttress installed outside the building footprint comprised of (256) 6’ diameter columns installed to 82-ft depth in shear panel rows. The columns were installed using CI-CMC twin axis which contributed to an efficient operation that more easily penetrated obstructions than other soil mixing means. Building foundations were supported on (277) 30” diameter Aggregate piers installed to depths of 22-ft.
