RETROFIT MEZZANINE/OFFICE LEVEL
MORRIS-SHEA PROJECT COMPONENTS:
TEMPORARY SHORING – 168 TOWERS
CFA FOUNDATION PILE – 422 PILES
Morris-Shea completed a continuous flight auger (CFA) deep foundation retrofit at a 1 million SF online retailer distribution center in Newnan, GA. The recently constructed warehouse at The Cubes of Bridgeport required significant modifications to increase load capacity to accommodate a new mezzanine level for additional storage and office use. Morris-Shea reviewed the original building redesign plans and developed a value-engineered alternate that improved support for the elevated area within the facility. The revised deep foundation design also reduced construction expense by approximately 25% and expedited project completion.
MORRIS-SHEA VE-ALTERNATE DESIGN
The new project design, as developed by the Morris-Shea team, required the installation of temporary shoring towers for the existing 10-inch square columns, cutting and removal of the existing columns, removal of the spread footings, and construction of high capacity CFA piles with new pile caps. This work was followed by the installation of new 18-inch wide flange columns, welding the new column to the old one, and finally removing the shoring towers and patching of the floor. Morris-Shea’s VE-alternate specified the removal of the existing concrete floor slab at each column location to allow the installation of new pile caps.
CFA PILE INSTALLATION
CFA piles were installed with one TesCar CF4.5 and two IHC Fundex CD20D drill rigs working day shifts only. The rigs utilized special length masts to accommodate the height-restricted work environment. Pile spoils in the building’s interior were loaded by small excavators into compact dumptrucks and collected for transport off site.
The soil profile consists of intermittent layers of silts, clays and sands with dense sand at the pile tip elevation. The contractor performed 12 cone penetration tests (CPT) for each LNG containment tank to better determine soil conditions and potential variability. Morris-Shea’s in-house pile capacity software combined new CPT site investigation results with pile load test data from every DeWaal Pile installation since 1992 to accurately predict pile behavior at the construction site.
MOBILE CONCRETE PLANT
Grout for the CFA piles was supplied by a Morris-Shea in-house mobile concrete plant and delivered by the contractor’s own fleet of ready mix trucks. This expedited process allowed pile installation to proceed without any interruptions while maintaining exacting specifications for the concrete mix.