Using geosynthetics for macroencapsulation for CCR on-site clean closure

August 1, 2017

Coal combustion residuals (CCR) have been used for many years in the construction of berms and engineered structural fill applications, including embankments for highways, dikes, and levees. However, large, unencapsulated structural fill projects have become a focus of environmental concerns due to potential leaching of metals and structural failures. Cap-in-place of CCR surface impoundments is …

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Achieving zero leaks on a budget with geomembranes

June 1, 2017

For more than 30 years, the geomembrane industry has been told that “all geomembranes leak” (Giroud 1984), as if this were some foregone conclusion no matter what might happen from geomembrane manufacturing to the time it is put into service. But recently, the idea of “zero leaks” has been a hot topic at industry conferences, …

History of geosynthetics use on national forest roads

Introduction The objectives of this article are to document the long history of geosynthetic materials used in the U.S. Department of Agriculture (USDA) Forest Service and other rural roads, to document the many creative and useful ways geosynthetics have been used, and to promote the cost-effective uses of geosynthetics in road projects today, particularly on …

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Protecting geomembranes from animal damage

Resisting animal and insect attacks on geomembranes is an interesting problem. Geomembrane installers and manufacturers have had numerous geomembranes damaged by bears, deer, coyotes, birds, beavers, and ground squirrels (Figures 1 and 2). In most cases, the damage is incidental to something else the animal is seeking. Deer damage the liner with their hooves trying …

Part 2: New design models for MSE walls and slopes

Introduction The design of many geotechnical structures is based on limit-state conditions. For example, in designing gravity walls, the load exerted by the retained soil on the wall is based on an assumed active state of stresses. That is, the wall moves sufficiently outward, enabling the retained soil to mobilize its shear strength along a …

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PART 2 Functions and applications of geosynthetics in roadways

April 1, 2017

Introduction Part 1 of this article provided an overview of the various functions that geosynthetics can fulfill in roadway applications. These functions include separation, filtration, reinforcement, stiffening, drainage, hydraulic/gas barrier, and protection. Table 1 in that article identified a total of five roadway applications involving geosynthetics. For each of the five roadway applications, the table …

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PART 1 ‘Geosynthetic reinforced soil 101’ leading to rational design of MSE walls and slopes

Introduction The design of many geotechnical structures is based on limit state conditions. For example, in designing gravity walls, the load exerted by the retained soil on the wall is based on an assumed active state of stresses. That is, the wall moves sufficiently outward, enabling the retained soil to mobilize its shear strength along …

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Flood impact reduction and streambank repair along Spy Run Creek

Background Spy Run Creek in Fort Wayne, Ind., is a 10-mile watercourse that drains several square miles on the northwest side of Fort Wayne. Spy Run Creek empties into the St. Mary’s River in downtown Fort Wayne, just upstream from its confluence with the St. Joseph River. The St. Mary’s and the St. Joseph rivers …

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Part 1: Functions and applications of geosynthetics in roadways

February 1, 2017

Introduction The geosynthetic products most commonly used in roadway systems include geotextiles (woven and nonwoven) and geogrids (biaxial and multiaxial), although erosion-control products, geocells, geonets (or geocomposite drainage products), and geomembranes have also been incorporated in a number of projects. These various types of geosynthetics can be used to fulfill one or more specific functions …

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Oh no! The GCL got wet! Now what?

Authors’ note: The conditions This project started in central California in July 2014, and we watched the weather forecasts on the nightly news and we were calm. A few weeks later, the project is running longer than expected, and now we are watching the Weather Channel and reading Weather Underground and Accuweather with more interest …