Dean Wickoren ENVIROTUBE Technical Director Industrial Fabrics, Inc. dean@envirotubes.com 913-221-5345 (mobile) Resume and Accomplishments (over 40 years experience) Frequently Asked Questions

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ENVIROTUBE Brochure

Capacity Chart

Product Data Sheet 4X6

Project Questionnaire

Hanging Bag Test

International Dredging Review
The geotube phenomenon

The Press of Atlantic City
A Line in the Sand. A.C.'s beach 'geotube' hold up to destructive waves.

GFR Engineering Solutions
Hold the ketchup!

Erosion Control Magazine
Geotextile Tubes Provide Coastal Erosion Protection in Ecuador.

Case Studies

Background

A series of strong coastal storms wreaked havoc on a South Jersey shoreline, consuming a wide path of heavily vegetated dunes and more than a dozen yards of beachfront separating a three-story condominium complex from the raging sea. The aftermath left this 18-unit complex in Sea Isle City, New Jersey defenseless if another series of storms should strike the shoreline. With several months of winter storms looming, and no signs of El Nino relenting, city officials were gravely concerned with saving this beachfront property and other surrounding real estate.

Product Information

Designed to protect shoreline beaches from the devastation caused by these coastal storms, high strength geotextile tubes are the latest in protection against the erosive forces of nature that occur every time waves, high tides and long shore currents collide with a vulnerable stretch of beach. The tubes are constructed of high strength polyester and filled with dredged material, or trucked-in sand (as in the case of Sea Isle City). Once filled, the tubes are covered with sand, creating a resilient base for dunes to protect against erosion and damage.

Geotextiles are designed to resist abrasion, tearing and puncturing, as well as endure pressure during filling and placement. Traditional materials, such as rock or concrete, can be much more expensive than the use of geotextile tubes. "The tubes are more easily removed, have a finite lifespan, and can have a far less permanent impact on the environment than conventional hard structures," stated Orrin Pilkey, director of Duke University's Study of Developed Shorelines.

Construction

Albrecht & Heun, the general contractor, began the project to restore the shoreline between 91st and 93rd streets only two weeks after the devastation to the Sea Isle City shoreline. With the aid of front-end loaders, backhoes, dump trucks and hydraulic equipment, Heun's six-man crew began installing 900 feet of ENVIROTUBE 12 x 12 tubing with hopes of protecting the condominium complex from future storm damage. During the first week, workers built a temporary road to the beach and brought equipment for the replenishment and filling of the ENVIROTUBES. A crane lifted rocks and debris from the site so the tubes could be placed on the beach without the possibility of being punctured.

The tube rests on a polypropylene scour apron that serves to inhibit undercutting of the tube's foundation if the sand layer is removed by future storms. In the Sea Isle City project, Propex® Geotex® 4 x 4 was specified in the construction of the scour apron.

The process began with a trapezoidal trench one foot below grade, onto which the apron was placed. The scour apron also serves to reduce local erosion caused by the flow of water during the filling process. Three tubes, 30 feet in circumference, were then set on the apron and a sand and water slurry was trucked and pumped into the tubing using an IMS submerged cutterhead dredge, through a 10-inch discharge line. The water percolates out through the fabric, leaving a dense sand-filled structure.

The tube was then pumped until full, with heights reaching 5.5 to 6 feet and widths of 12 to 13 feet. The 900 feet of tubing contained nearly 1,900 cubic yards of sand when full. After the tube was completely filled, it was covered with an additional 1 to 2 feet of sand, creating an 8 foot high dune along the beach.

Tests at Sea Isle City showed some percentage of the fill were smaller than the fabrics opening size. Experience has proven that polyester fibers and yarns tend to expand when soaked and under pressure. This makes openings smaller and retains nearly all of the fill material. The role of surface tension in retaining materials can be observed when walking on the tube during filling. It is also believed that material cakes on the inside of the fabric casing, retaining even fine-grained materials. These filtration qualities point to additional uses of tubes for dewatering of industrial waste and contaminated materials.

Conclusions

The ENVIROTUBES 12 x 12 tube will remain on the beachfront for an indefinite period of time. Along the landward side of the tube, the wide berm of sand placed by the crew is intended to develop into a dune, working against the force of the sea to protect valuable beachfront property.

Within three weeks, the tubes had been successfully placed, restoring valuable shoreline and protecting the condominium complex. City officials were very pleased with the $163,398 investment in their ongoing struggle against beach erosions.

Three months later, the tubes were put to an extreme test when northeast storms slammed into the New Jersey shoreline. Cape May County was declared a national disaster area. The tubes held, and while the sand behind them was lost, the condominium complex was not damaged. The success of this and other projects will aid engineers and contractors in reclaiming our shorelines and stemming erosion.