GEO Target: Bonita Beach, Bonita Springs, Florida
The west coast of Florida took a heavy hit during Hurricane Ian, leaving many coastal and beachfront homes vulnerable to foundation damage caused by soil washout and erosion. One such home in beautiful Bonita Beach required urgent foundation stabilization to protect the structure from ongoing damage. Coastal Foundation Solutions was proud to deliver a reliable underpinning solution tailored to the unique challenges of this waterfront property.
Project Background: Soil Erosion and Foundation Challenges After the Storm
Hurricane Ian’s storm surge and flooding caused significant soil displacement and washout in Bonita Beach, weakening foundations of many homes along the coast. Our client’s home exhibited signs of distress due to these forces, necessitating a thorough approach combining underpinning with advanced seawall protection.
With prior experience in the area and deep understanding of subsurface conditions, Coastal Foundation Solutions developed a strategic plan to install underpinning piles that would reinforce both the internal and external foundation components.
Solution: High-Capacity Helical Micro Pulldown Piles and Innovative Site Work
In March 2023, our team conducted a static load test using Helical Micro Pulldown Piles. The original test piling demonstrated impressive capacity, securing 32 tons in compression at a depth of 34 feet, with 4,800 ft/lbs of torque (equivalent to about 24 tons in compression). Additionally, a 5-inch grout column was installed, contributing an extra 8 tons of compressive strength—boosting the pile’s total capacity substantially.
The project’s complexity required us to install 28 underpinning piles around the home’s perimeter. During excavation, we encountered existing grade beams approximately 30-36 inches below grade, measuring about 30 inches wide by 12 inches deep and reinforced with steel. This required careful digging to uncover and assess the condition of these structural elements.
We discovered significant groundwater infiltration beneath the footing, likely due to proximity to the Gulf of Mexico and an adjacent canal system. This led to 22 hours of dedicated excavation and dewatering to create a stable environment for pile installation.
Inside the home, we installed 20 underpinning piles to substantially increase the foundation’s load-carrying capacity and ensure long-term stability.
Managing Helical Pile “Refusal” and Site Conditions
During installation, several piles met “refusal” or “spin-out” conditions—where the pile stops penetrating while still rotating due to encountering dense soil layers or bedrock. This phenomenon affects the pile’s load capacity and requires static load testing to accurately determine bearing strength. In cases where refusal occurs on bedrock, capacity is assumed to be limited by the structural strength of the lowest helix plate, assuming bedrock is sufficiently strong.
Despite these challenges and extensive groundwater issues, our expert crew successfully completed the underpinning and foundation stabilization work with minimal disruption.
Results: Stronger, More Resilient Foundations for Coastal Living
Thanks to the careful engineering and skilled installation, the underpinning piles significantly strengthened the foundation, protecting the home against future soil erosion and foundation movement.
The project demonstrated how advanced helical pile technology, combined with a comprehensive understanding of local geotechnical conditions and environmental factors, can provide effective and durable foundation solutions in coastal Florida.
Products Installed
- SS150 8” x 10” x 12” 76″ Helical Micro Pulldown Piles
- 16” Helix Extensions for refusal conditions
Frequently Asked Questions (FAQ)
What causes “refusal” or “spin-out” during helical pile installation?
Refusal occurs when soil resistance exceeds the downward thrust of the helical plates and the excavation equipment’s crowd pressure. It’s common near dense soil layers or bedrock and affects how the pile’s load capacity is measured.
Why was dewatering necessary for this project?
Groundwater infiltration under the foundation was detected, likely due to the home’s location near the Gulf and canals. Removing excess water was critical to ensure proper pile installation and foundation stability.
How do underpinning piles improve foundation stability in coastal areas?
Underpinning piles transfer the structural load to deeper, more stable soil layers or bedrock, preventing further foundation movement caused by surface erosion or soil displacement.
About the Author
Charlie Garcia, a Florida-certified building contractor and marine construction expert with over 25 years of experience, led this project. Based in Cape Coral, Charlie is licensed under Florida License #CBC1252534 and #CBC1263386 and holds certifications as a Certified Helical Piling Inspector, Deep Foundation Contractor, and Foam Injection Contractor. His expertise in foundation stabilization and marine structural restoration is trusted throughout Southwest Florida’s coastal communities.
Is your Bonita Beach or Southwest Florida waterfront home at risk due to foundation damage or erosion? Don’t wait for further damage. Contact Coastal Foundation Solutions for a free consultation and expert foundation stabilization plan tailored to your property.
Call (239) 555-1234 or visit www.coastalfoundationsolutions.com/contact today to protect your home and investment.