Helical piles were determined to be the effective and practical solution for the project. The engineer design for the pool and deck included twenty-eight (28) “Chance” 2.875-inch OD by 0.276-inch wall helical piling. The round shaft helical piles with 8”-10”-12” triple-helix lead sections were utilized. The piles would support design working loads ranging from 12 to 30 kips. With the presence of the fill and weak native soils near the original ground surface, a minimum helical pile depth of 21 feet, as measured from pool deck subgrade elevation, was required
A Kubota track excavator was fitted with a custom mounting bracket to support the drive head with a rated output torque of 10,000 ft-lb. Peat was discovered during the preliminary helical pile installation, requiring additional pile advancement and affecting torque accuracy. Additional extensions were required reach the specified load capacity and structurally-tolerable parameters. The piles were advanced to depths ranging from 21 to 45 feet to achieve torque-correlated ultimate capacities of at least twice the design working loads. The tops of the piles were cut to design elevation and tailored with new galvanized construction brackets to be cast into concrete grade beam. The 28 helical piles were installed in two days.
The helical piles were installed by Coastal Foundation Solutions (CFS), a Certified Installer of Seawall Savers and Chance Helical Foundations Systems.
Twenty-eight (28) CHANCE 2 7/8” round shaft helical piles with an 8”-10” 12” triple-helix lead section were installed with a 10K Eskridge drive head. The Kubota excavator progressed the extensions to lengths on the order of 21-45 feet to achieve final installation torques. The ultimate capacities of at least twice the design working tension load of 20 kips
Ninety-eight (98) “CHANCE” (RS2875.203) round helical extensions were installed to corresponding capacities to secure tension load of 20 kips.
The helical foundation pilings were affixed with a galvanized 7’ by 7” termination cap.
This helical piling installation was completed in just three days due to access constraints.