Rail project required separation, filtration, reinforcement

February 1, 2015  |  Case Studies, Features

Introduction The Canadian National Railway (CN Rail) wanted to build an additional six-track extension at its Transcona Yards in Winnipeg, Manitoba. Heavy railcars were expected to pass over this extension area and CN Rail was looking for an economical, efficient, environmentally friendly, and techn…
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Polymeric marine mattresses

October 1, 2014  |  Case Studies, Features

Case studies highlight marine mattress applications By Jeff Fiske Introduction Marine mattresses are rock-filled containers constructed with advanced UV-stabilized co-polymer geogrid materials. Geogrid panels are laced together to form mattress-shaped baskets that are filled with small stones simila…
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Allowable stress on geonets based on laboratory creep tests

October 1, 2014  |  Features

By Dhani Narejo and Sam Allen Introduction The first article in this three-part series presented compressive stress-strain behavior of several different geonet structures. The collapse, or rollover, does not occur for many types of geonets. In the absence of a rollover, the compression of geonets is…
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Allowable stress on geonets based on laboratory creep tests

August 1, 2014  |  Features

By Dhani Narejo and Sam Allen Introduction This article focuses on biplanar geonets to the extent of the possible tendency for the two sets of integrally joined ribs to roll over on one another while load is applied. The significance of such a rollover is a reduced transmissivity value as compared t…
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Geosynthetics committee examines drainage issues

July 17, 2014  |  Features

Proposed ASTM standard for stormwater catch basin filters. ASTM International in a July 17 press release announced a proposed new standard that will offer a means to reduce the impact of contaminated stormwater entering local drains. WK45326, Specification for Stormwater Catch Basin Filter, will aid…
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Geonet structure, short-term stress/strain behavior, and creep test methods

June 1, 2014  |  Features

Part 1: Allowable stress on geonets By Dhani Narejo and Sam Allen Introduction Several types of geonets are used in numerous applications worldwide. Examples of the types of geonets include biplanar, triplanar, spiked or profiled, cuspated, tubular, and three-dimensional (3-D) filament meshes (see F…
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The influence of soil type on interface behavior under pullout conditions

June 1, 2014  |  Features

Part 3: European experience in pullout tests By Nicola Moraci, Daniele Cazzuffi, Lidia Sarah Calvarano, Giuseppe Cardile, Domenico Gioffrè, and Piergiorgio Recalcati 1. Introduction The rapid increasing application of geosynthetics as reinforcement elements for earth structures requires a car…
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Long-term pavement testing by FHWA

April 1, 2014  |  Features

Contamination by subgrade soil causes deterioration in pavements from progressive loss of effective aggregate base thickness. Introduction A major deterioration factor in pavements is the progressive loss of effective aggregate base thickness because of contamination by subgrade soil. In the service…
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ASTM geosynthetics standards revising to ISO ‘geo terminology’

October 1, 2013  |  Features, News

By Bob Mackey Geo terminology—The current issue The ASTM Committee D35 on Geosynthetics was established to develop standards on test methods, guides, practices, and specifications for geosynthetic materials. A component critical to the development of these standards is an agreement within the …
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Market impacts for geosynthetics from the regulation of coal ash

August 1, 2013  |  Features, News

By Boyd Ramsey and Andrew Aho Authors’ note to readers: This is a fast-moving topic where situations change as time and political positions evolve. It is the authors’ intent to report on the current situation and implications “at the time of presentation [April 2013],” provid…
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