Crew faces many challenges in completing Newry-to-Dundalk roadway

By Ron Bygness The A1/N1 Newry-to-Dundalk link road is a cross-border, design-and-build route that runs between the Cloghoge roundabout, south of Newry, Northern Ireland, and the Ballymascanlon interchange, north of Dundalk, Republic of Ireland. The new road forms part of the main Dublin–Belfast corridor and is the largest cross-border roads project to date. This major …

Geotextiles

These products are engineered to provide cost-effective solutions to meet specific design requirements for separation, reinforcement, filtration, drainage, and protection applications. Although engineers have developed numerous applications for geotextiles, there are five major functions: separation, reinforcement, filtration, drainage, and protection. The major geotextile classifications are woven, nonwoven, and knitted. Generally, woven fabrics exhibit high tensile …

Grand Isle to get storm-surge protection before 2009 hurricane season

By Ron Bygness Ending more than a dozen years of debate regarding plans to upgrade storm-surge protection for Grand Isle, La., Gov. Bobby Jindal’s administration signed an agreement in April with the U.S. Army Corps of Engineers (USACE) for a $50 million project to rebuild the island’s decimated flood barriers. Grand Isle is located on …

Geogrids

Geogrid products are designed for reinforcement and, characteristically, are integrally connected to elements separated by in-plane apertures. Geogrids form a distinct category of geosynthetics designed for reinforcement. These products are characterized by a relatively high tensile strength and a uniformly distributed array of large apertures (openings between the longitudinal and transverse elements). The apertures allow …

Geosynthetic clay liners (GCLs)

Bonding clay to geosynthetic materials has created an economical, long-term solution for many applications. Geosynthetic clay liners (GCLs) are hydraulic barriers made of clay bonded to a single geosynthetic layer or to multiple geosynthetic layers. Because of its low permeability, swelling capacity and relative abundance, natural sodium bentonite is the preferred clay component of GCLs. …

Drainage materials

Geonets, sheet drains, edge drains, and prefabricated vertical drains are all designed to offer strong, performance-enhancing alternatives to traditional drainage systems. Geocomposite drainage systems are engineered to minimize costly, conventional graded-aggregate and/or perforated-pipe subsurface drainage systems. Geonets, sheet drains, pavement edge drains and prefabricated vertical drains (PVDs) have reached acceptance as state-of-the-practice because they provide …

Geocells

Geocells are engineered for protection and stabilization applications. They are often used to help improve the performance of standard construction materials and erosion-control treatments. Geocell products are three-dimensional, expandable panels made from high-density polyethylene (HDPE), polyester or another polymer material. When expanded during installation, the interconnected strips form the walls of a flexible, three-dimensional cellular …

Erosion control materials

These products are designed to help solve erosion- and sediment-control problems and to provide long-term stabilization by establishing and maintaining vegetative cover. Erosion-control products give engineers ready solutions for one of the fastest-growing design niches. Many of these products work with vegetation to form a biocomposite solution to erosion. The charts in this section are …

Geosynthetics in the Greater Grand Forks Greenway

By Adam Regn Arvidson The turf reinforcement mat (TRM) in the Red River Greenway project is Enkamat, manufactured by Colbond, a Dutch company with production facilities in Europe and the U.S. The 3-dimensional nondegradable matting is made of continuous nylon or polypropylene filaments fused at their intersections, with 95% of the matting open. The 3-D …

Strength without density: Geofoam at work on the CAS green roof

An innovative redesign transforms the California Academy of Sciences. By Shelby Gonzalez Introduction The California Academy of Sciences (CAS) in San Francisco has completed a transformation. Its innovative redesign has already gained international recognition as a cultural icon. Under one “living roof,” the new Academy contains a planetarium, an aquarium, and a natural history museum. …