ARTICLE
How long can a Geotube® shoreline protection system last?
Decades—even under some pretty tough conditions. Here’s an example.
Nearly 25 years ago, Geotube® containers were installed at Atlantic City, New Jersey to protect more than a mile of shoreline and the famous boardwalk from storms and extreme high tides. The tubes were filled and covered with sand from the local area and planted with dune grass to give the appearance of a natural dune.
But only three months after project completion, Hurricane Luis produced three days of storms and 10- to 12-foot waves that pounded the shoreline. Once it was over, residents could see that sand had been washed from the ocean side of the Geotube® containers, but on the other side, there was no damage to property or loss of shoreline. The local media called it, “a line in the sand… there will be no more erosion past that line.”
Sand and vegetation was replaced and those same Geotube® containers have continued to protect the Atlantic City shoreline from storms, wind and waves. More severe weather in 2012, Super Storm Sandy, damaged the north end of the boardwalk, which was not protected by Geotube® containers, but the south end performed as designed and withstood the waves.
Why are Geotube® containers so successful in Atlantic City?
1. Massive size
Each Geotube® container is a monolithic structure—100 feet long, 7 feet high and a circumference of 30 feet. The circumference can be as much as 50 feet, which gives engineers the flexibility to select the most appropriate size of Geotube® to withstand damaging forces from waves and ice.
2. Durable Construction
Geotube® containers are made from high-tenacity polypropylene multifilament yarns, arranged in a stable weave. This material is highly resistant to UV, inert to biological degradation and resistant to chemicals, alkalis and acids. This material is also engineered to withstand scouring and punctures and can be reinforced for more demanding environments with a debris shield or polyurea coating.
Newly introduced Geotube® Durability Engineered Composites offer even more robustness and abrasion/damage resistance for shoreline projects. This advanced container incorporates a highly UV stabilized crimpled fiber that shields and cushions a woven geosynthetic underneath and also enables sand and soil entrapment so vegetation can easily be established. Watch our future e-news issues for more info.
3. Stable structure
Engineers incorporated Geotube® containers into the natural structure of the sand dunes. Geotube® containers form the core of a more storm-resistant sand dune structure. Although the Geotube® containers may be uncovered during a storm, the help limit erosion primarily to the ocean-side area and can be easily covered up afterwards.
