In Naples, Florida at St. Vincent’s at Pelican Bay is a lakefront village of garden-style villas. Built in the early 1990’s, this two-story development offers a guard gated entrance with lovely households, featuring lake and swimming pool views and gulf access.
The property had an aging concrete sheet pile bulkhead that the community pool was situated on. The pool is located on a peninsula with water on three sides. At some point in the past, the seawall seams begin to enlarge allowing soil migration from beneath the concrete pool deck to escape. For over 5 years the property has been experiencing recurring sinkholes behind bulkhead. The property owner had the seams filled with hydraulic cement and flowable fill over the years, but the sinkholes kept returning. With new sinkholes opening again, they decided to call Coastal Foundation Solutions.
Coastal Foundation Solutions consulted with the owners, property manager and inspected the bulkhead along the pool peninsula on the lakefront. The home owners association was concerned about the regular void formation beneath the concrete, but was also concerned about the seawall seams leaking. It became clear that the original bulkhead was the source of the problem. The original concrete seawall/bulkhead was constructed 30 years ago, and over the years had likely experienced deterioration which allowed water to travel through the seams. As water washed away fine soils, persistent cavities kept forming behind the bulkhead and beneath the pool surface. The Coastal Foundation Solutions team determined that Deep Foam Injection would provide a perfect resolution for preventing future soil failure issues behind the lakeside bulkhead, and that all work could be accomplished without disrupting the pool surface area.
Because the property is located within an energetic community that utilizes the pool on a regular basis, it was paramount any solution would have to take into account significant resident activity. Coastal Foundation Solutions elected to install an injection grid that created one row of injections to fill the voids. This process would fuse together the deeper soils, and seal the pathways where water was traveling through the bulkhead. Injected under high pressure, this product seals and fills voids all in one easy procedure. Using very tiny injection ports (as small as 5/8”), holes are bored through the concrete and foam is then advanced through the ports to create the desired sealing effect.
In addition, the seawall seams where sealed from the outside face of the concrete seawall slabs utilizing our proprietary process. This system utilizes permeable foam installed into seams and a High Density Poly Ethylene (HDPE) panel being affixed to the seawall with 316 Stainless Steel Fasteners.
Coastal Foundation Solutions Dremel grinded out fissures in the concrete seawall cap and injected a two part epoxy adhesive into cracks to cease further water intrusion. The completed project was professionally finished with dual coats of a light grey two part epoxy paint being applied to the surface of the concrete seawall cap.
After just three days on site, Coastal Foundation Solutions crew grouted the soils behind the older sheet pile bulkhead along the perimeter of the pool. The soils were stabilized to guard against future sinkhole development, the seams were additionally shielded to insure no future soil loss occurs. All fissures in concrete cap were filled with epoxy and the cap was sealed with epoxy coating. The process that Coastal Foundation Solutions employed was the least disruptive answer available in terms of noise and time, and all work was completed without any disruption for residents.