GEOWEB Hard-Armored Shoreline Protection System Protects Vulnerable Riverbank from Erosive Forces The extreme El Niño event caused the western Pacific to warm, developing atmospheric convection and increased rain- fall. The storm events caused catastrophic flooding and severe erosion in the eastern equatorial region of Ecuador and Northern Peru. A portion of the Zarumilla River, located in the remote Tumbes region in Northwestern Peru, was expe- riencing severe erosion and required a shoreline protection solution to prevent further deterioration of the riverbank. The GEOWEB® Shoreline Protection System was selected to protect the Zarumilla riverbank against future storm events. The GEOWEB system with concrete infill provides economical, hard-armored protection of slopes and chan- nels exposed to high flow velocities and high shear stresses. The system has been proven to withstand sustained flow velocities over 36 ft/s (11 m/s) and shear stresses of 20.9 psf (1.0 kPa), outperforming rip-rap, gabions, and other conventional hard armor strategies. The product was shipped to the site in September 2020, and installation was complete by December 2020. The project was completed on schedule and within budget. The GEOWEB® Shoreline Protection System is performing to expecta- tions and will provide much-needed protection to the Zarumilla River and the communities that depend on it when the next major storm hits. GEOWEB Geocells Used for Erosion Protection of Canal Floodwall Erosion of the 17th Street Canal’s flood protection system was a major concern for the Southwest Louisiana Flood Protection Authority-East. The Authority required a solution to protect the canal’s slope against erosive forces and prevent a floodwall breach in the event of a tropical storm event. To mitigate channel slope erosion, engineers chose the GEOWEB® Confinement System to stabilize the slopes along the Metairie side of the drainage channel. By confining the infill material, the GEOWEB system prevents flow from causing scour and erosion on slope surfaces. The construction company installed approximately 380,000 square feet of GW40 (mid-cell size, six-inch deep panels) over a woven geotextile along the canal’s slope and infilled the cells with crushed aggregate sized based on research and testing at Colorado State University hydraulics lab. The GEOWEB System: • allows the use of smaller, less expensive rock—even waste rock which decreases installation and transportation costs. • creates a permeable, cover when drainage is desired but vegetation cannot be established. • resists high velocities and tractive forces.
Design Support & Re- sources for the GEOWEB SystemApplications The engineering team at Presto Geosystems works closely with engineers and project planners, offering free project evaluation services and on-site support. Our rec- ommendations will de- liver a technically sound, cost-effective solution based on four decades of accredited research and testing data. Please contact our knowledge- able staff and network of qualified distributors and representatives to discuss your project needs today.
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csengineermag.com
april 2022
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