A portion of the Cape Hatteras Ferry Terminal’s seawall was in serious need of repair. The seawall needed a solution to prevent further damage and ensure safety to the area.
Hatteras, North Carolina is home to the iconic Cape Hatteras Lighthouse, boasting over 50 miles of beautiful shoreline. While the year-round population is about 3,000-4,000 people, this number spikes in the summer months to over 50,000+ visitors per week. The Coast Guard Station at Hatteras Inlet is also located on the southern end of the island. The nearby ferry terminal for this wonderful island is both necessary, and enjoyable for residents and visitors alike.
When the original seawall was constructed, the concrete piles were installed using water jetting, a process of using high pressure water to create cavities to install concrete piles into the ground to support structures above. Once the row of piles were in place, concrete panels were set and sealed in between the piles. The seal between the precast panels and the piles at the ferry terminal were causing soil to pull through the wall, and into the ocean. As a result, sinkholes began to form behind the seawall near the Coast Guard Station Hatteras Inlet. The NCDOT contacted URETEK for an environmentally friendly, non-invasive solution to prevent further loss of soil behind the seawall.
In order to fill the present voids and sinkholes in this environmentally sensitive area, injection of URETEK’s hydro-insensitive structural polymer, also
known as high-density polyurethane resin, along the seawall would need to take place. URETEK’s Deep InjectionTM Process would allow the polymer material to expand, cure, and therefore fill any present voids or sinkholes. The process would also seal the panels and piles from the back side of the wall, preventing the future formation of sinkholes.
To start the project, the joints of the panels needed to be located with the help of trained divers who would also provide a live-stream video of the repair process for quality assurance. Next, injection tubes were driven down to depths of 20 feet along the seawall, and technicians then began to inject the URETEK polymer material. Extra precautions were taken during injection, to ensure the project would be non-disruptive to the environment and Hatteras residents.
All soil leaks were successfully repaired, the sinkholes forming behind the wall were filled, and the soil was stabilized. The newly sealed joints, insured a stable, and functioning ferry terminal for residents, and vacationers alike.