Composite Geosynthetic Design Used to Protect Expansion Levee

摘要

Port Manatee, an international port located in Palmetto, Florida provides quick access for businesses to import and export goods all over the world. The port needed to be enlarged due to increased channel water traffic. The heavy construction involved the dredging of a 12.19 meter (40 ft) deep entrance channel, turning basin, and berthing area. To accommodate the dredging material from the construction work the existing dike at the site needed to be enlarged. Because of the size of the dike and the poorly graded sandy soils present on the site, both geogrids and Composite Turf Reinforcement Mats (C-TRMs) were needed to stabilize the dike and the slope as it was being constructed. Along with the highly erodible soils, the engineers faced a high rainfall factor along the coast, making high performance erosion protection for the dike a necessity. The first step was to stabilize the dike face. Biaxial (BX) geogrids were used to provide veneer stability of the slope of the containment dike, while Uniaxial (UX) geogrids were used to address global stability. The next step was to stabilize the surface of the slope and to establish vegetation as soon as possible. The Army Corp of Engineers had selected C-TRMs to do the job. The composite design of the TRM would provide immediate erosion protection for the erodible soil and the newly distributed seed, and the high strength three-dimensional netting structure of the TRM would stay in place to permanently reinforce the root and the stems of the vegetation against the severe erosive forces expected on the slope. The project contractor was pleased with the easy installation and low maintenance requirements of the C-TRMs. With the aid of these products, the Port Manatee containment dike was well stabilized and protected from erosion without the use of hard armor materials, saving project money and adding aesthetic appeal. Now that the dike has been reconstructed, the dredging projects can continue, and the channel can be expanded to accommodate the water traffic moving in and out of the bay.