TEXTILES.ORG
EDITOR’S NOTE
Complete information regarding the parties and all Maccaferri solutions and products involved in the award-winning reconstruction of the Fort Pierce City Marina were not included in the original article.
–R.B.
In rebuilding the Fort Pierce City Marina, the storm protection breakwater system was anchored by a 10.5-acre peninsular island, known as Tern Island, which shelters the marina from large open water fetch and harsh wave climates to the south and southeast.
This island includes: (a) a T-groyne with stabilized, crenulated beaches on the windward side of the island; (b) a coastal sand dune in the island center; and (c) a bench for oyster recruitment and mangrove planting along the leeward side.
The project foundation consists of nearly 10,700 linear feet of geotextile containment structures—with 30ft- and 45ft-circumference geotextile tubes and the smaller geotextile bags.
These structures were used in conjunction with 250,000 square feet of polymeric marine mattresses to establish the perimeter of Tern Island and to provide a foundation and structural core for the groynes. Approximately 35,000 tons of limestone armoring units were used to provide structural integrity to the breakwater system while providing ecological enhancements.
To achieve the island design elevations specified, four geotextile tube configurations were used. Single geotextile tubes were used in shallow water locations in the central portion of the island, while two-tier configurations were used in the deeper portions of the island.
One configuration consisted of a single 45ft-circumference bottom geotextile tube and top layer of sandbags and was placed along portions of the perimeter for oyster bench/dike creation. Another two-tier configuration was used in deeper water, consisting of two base geotextile tubes and a single top-tier geotextile tube.
A pyramid stack of 30ft-circumference geotextile tubes was used for the structural core of groyne #1, while a pyramid stack of 45ft-circumference base geotextile tubes was placed along the leeward side of the island to maximize the oyster bench area. The polymeric marine mattresses were installed in conjunction with the geotextile tubes and served as a critical component for the successful installation and structural protection of the island.
PROJECT HIGHLIGHTS
Client
City of Fort Pierce, Fla.
Main contractor
Cashman/Lucas Marine
Designer
Tetra Tech
Geosynthetic products
MacTube®, MacBag®,
Polymeric Marine Mattresses
(all by Maccaferri Inc.)
Construction dates
February 2012–May 2013