Wynnhaven Beach & D-84

Technical Description:

• Products used:
• ArmorFlex® Class 70
• ArmorFlex® Class 85
• Area: 28,629 SF

Eglin Air Force Base, located in the Florida Panhandle, needed to construct two landing areas along the Santa Rosa Sound and Choctawhatchee Bay. The landing areas would provide the 22nd Marine Expeditionary Unit of Camp Lejeune, North Carolina, a place for military training exercises which included using LCAC-50 hovercrafts and other amphibious assault vehicles. These tanks would be unloaded from battleships and banked onto beaches that were armored with the ArmorFlex articulating concrete block (ACB) system.

Peterson Engineering originally designed the beach protection and armament system using precast concrete slabs with upper and lower toewalls to prevent scour and undermining of the system. As a final design approached, the engineer was less comfortable with the long-term performance of precast concrete slabs. A specific concern was the possible cracking of the concrete which would occur if the sandy foundation developed scour problems.

The final design used an ArmorFlex system of Class 70 and 85 blocks with polyester cables and platypus anchors located at the top corners of each mat. The system also included a Geotex 111F monofilament geotextile directly below the block. The ACB mats were custom-made with the open cell block located above the mean water level and the closed cell block below it. The blocks were sized to handle the stresses from loaded hovercrafts that would not only be harbored on the blocks but would also rotate rapidly on the blocks as they departed and arrived. It took approximately three days for the ACB system to be installed for each location.

Technical Description:

• Products used:
• ArmorFlex® Class 70
• ArmorFlex® Class 85
• Area: 28,629 SF