Pinckney Hill Plantation had highly expansive soils and very loose soils from depths of 10' to 27' where they desired to build a 22,000 square foot residence. The access to the proposed residence included a narrow dirt plantation road that limited the type of equipment that could be brought to the site.
Due the unknown soil conditions and limited access Barkley Engineering provided the options of either helical piles or auger cast piles. Helical piles were selected because of their ability, cost savings and their ability to provide loading data for each pile based on installation torque. A helical pile configuration consisting of a 2-7/8 inch outside diameter round shaft with an 8"-10" double-helix lead section was selected. The piles were installed with a drive head attached to a Bobcat %35 and were installed to a minimum of 6,000 foot/pounds torque. Each helical pile was advanced to a depth of 32' below grade. Each pile was attached to the footing with a Foundation Support Works new construction bracket. The ultimate capacity of the production piles was monitored during installation with differential PSI gauges and a shear pin indicator. The installation of 208 helical piles took only 7 days.