MORRIS-SHEA PROJECT COMPONENTS
RESTRICTED ACCESS INSTALLATION
225 DEWAAL SCREW PILES: up to 55’
DEWAAL SCREW PILES:
– Value engineered alternate
– No spoils
– Accommodates height restriction
– Economical temporary casings
Morris-Shea (MSB), a leading deep foundation contractor, installed a deep foundation system for the construction of a parking structure and office building at the nCino Headquarters in Wilmington, NC. The 640 car, four story parking deck and 90,000 SQ FT, three story office building expand the corporation’s headquarters footprint. The Morris-Shea team utilized a PVE 90 Drill Rig and Schwing Concrete Pump to install 170 12-inch diameter DeWaal piles at the building site. MSB drilled 147 14-inch diameter piles for the parking structure’s deep foundation. The DeWaal piles were drilled to depths of 40-feet. The unique design of the DeWaal Pile System was ideal for this application in loose to medium dense subsurface soils and sand.
DEEP FOUNDATION PILE SYSTEM
DeWaal drilled, full displacement, cast-in-place concrete piles were installed by a powerful, fixed mast drill rig capable of applying high rotational torque and crowd forces to the unique tool. This single-pass process densified the soil, improved shaft friction, and increased overall pile capacity. As the DeWaal tool advanced into the ground, the
partial displacement auger transported soil to the full displacement element. Prior to lifting the tool, the drill stem was filled with a self-consolidating, high slump, coarse aggregate concrete. It functioned as a tremie pipe from which pressurized concrete owed while the tooling was withdrawn
■ VE alternate to conventional augercast
■ Higher production rates
■ Reduced material expense
■ Improved load capacity
■ No drilling spoils
VALUE ENGINEERED REDESIGN
The Morris-Shea engineering team redesigned deep foundation construction specifications from 16-inch diameter and 14-inch diameter augercast piles to 14-inch diameter and 12-inch diameter DeWaal piles. The use of the DeWaal Pile System reduced material expense, increased production rates, and improved load capacity.
SOIL CONDITIONS / TESTINGS
Soil testing at the nCino building site determined that the subsurface conditions included loose to medium dense existing fill, loose to medium dense silty sand, and medium dense to very dense sand throughout the Wilmington, NC project Morris-Shea performed compression testing on 12-inch and 14-inch diameter DeWaal piles.