Case Study
Ponce Inlet, FL
SITUATION
A coastal foundation pool design on the beach at Ponce Inlet, FL required accounting for several site-specific variables: loose, poorly-graded beach sand, active erosion processes and a water table typically within 2-4 feet of grade due to tidal influences. These conditions preclude conventional shallow foundation systems and require a deep foundation solution capable of resisting axial compression, uplift, and lateral loading independent of near-surface soil stability.
SCOPE OF WORK
Cantsink LLC was contracted by Tropicana Pools, Inc. to furnish and install a helical pile foundation system for a residential in-ground beachfront pool structure. The anchor system was engineered by AllAquatic Engineering to resist three primary failure modes associated with beachfront pool installations:
Tilting / differential settlement — from non-uniform bearing capacity in loose sand
Heaving — from hydrostatic uplift pressure and buoyant forces on the pool shell
Washout / lateral displacement — from erosion and wave/current action undermining the surrounding soil matrix
ANCHOR SYSTEM
The engineered design specified 23 helical piles, each fitted with an 8"/10"/12" triple-helix configuration, rated for a working load capacity of 20 kips per pile and an ultimate capacity of 40 kips. This configuration was selected to evenly distribute structural loads across multiple grade beams, providing reliable support for the pool shell and its associated load-bearing elements. The scope of the anchor system was limited to the pool structure itself and did not extend to support of the pool deck or surrounding hardscape.
RESULT
Helical piles were driven to an average depth of 14 feet below grade, with each pile achieving the required installation torque and target depth as specified by the engineering design. Following installation, the piles were cut to the correct elevation and capped per specification, completing preparation for the pool structure's foundation. The project was not without its challenges. Crews worked in corrosive salt-air conditions along the Atlantic coastline, in temperatures exceeding 98°F. Despite these demanding field conditions, the installation was completed successfully and on schedule. This project underscores a core principle of coastal foundation work: with an experienced installation team and sound engineering, no site is too challenging and no load requirement too demanding for a properly designed helical pier system.
