Recap of GRI-22 Conference in Salt Lake City

June 1, 2009  |  News

By Bob Koerner The 22nd GRI Conference took place on Feb. 27, 2009, during the last day of a very successful Geosynthetics-2009 Conference and Trade Show. GRI-22 was also successful and had 18 papers on the theme “Its All in the Details” (geosynthetic details are critical to any long-ter…
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Henderson re-elected

June 1, 2009  |  News

By Andrew Aho GMA’s managing director, Andrew Aho, announced April 20 that John Henderson was re-elected to serve a second term as chairman of the GMA Executive Council. “We appreciate John’s service and look forward to his continued leadership as chairman,” Aho said. The GMA…
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GMA Lobby Day helps U.S. Congress connect with geosynthetics

June 1, 2009  |  News

By Andrew Aho Representatives from 10 member companies of the Geosynthetic Materials Association traveled to Washington, D.C., March 16-17 to participate in another successful GMA Lobby Day. The annual event is part of GMA’s ongoing government relations program, which advocates for increased u…
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Geomembranes and reservoirs

June 1, 2009  |  Q&A: GMA Techline

By Timothy D. Stark Q: Is it possible to cover an entire reservoir with a geomembrane? In addition, is it possible to line an entire reservoir or lake with a geomembrane? A: The answer is yes to both questions. Geomembranes are frequently used to cover reservoirs, especially in California (USA) for …
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Fixing an exposed landfill cover

June 1, 2009  |  Products

By Timothy D. Stark Q: The following photo shows a landfill cover with a gray material exposed. Is this good? If not, what should be done? A: A close-up of the gray material indicates that it is the geomembrane that is part of the final cover system for this landfill. This is not good and … <…
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Design strength for GCLs

June 1, 2009  |  Products

By Timothy D. Stark Q: What design strength should be used for GCLs? A: If the GCL is not encapsulated between two geomembranes, the slope design should/must assume that the GCL will be fully hydrated at a low normal stress (e.g., 5–10 psi for a liner system). If the GCL will be encapsulated b…
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Maximum slope angle for geosynthetic-lined slopes

June 1, 2009  |  Q&A: GMA Techline

By Timothy D. Stark Q: Is there a maximum slope angle for geosynthetic-lined slopes? A: Yes there is, and the slope angle should not exceed the lowest geosynthetic interface friction angle, δ, of the system. The slope angle should not exceed δ because this condition can/will lead to tens…
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The effects of heat on Subtitle D composite liner systems

June 1, 2009  |  Products

By Timothy D. Stark Q: What effect does heat have on a Subtitle D composite liner system? A: Heat can have many detrimental effects on a Subtitle D composite liner system. For example, heat can adversely affect the compacted low permeability soil liner by reducing its moisture content, leading to an…
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GCLs and hydraulic equivalence

June 1, 2009  |  Products

By Timothy D. Stark Q: Are GCLs hydraulically equivalent to a compacted low permeability soil liner? A: A good, but difficult, question. GCLs are hydraulically equivalent to low permeability soil liner in terms of advective flow. However, GCLs are not hydraulically equivalent to low permeability soi…
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The difference between strength parameters

June 1, 2009  |  News, Q&A: GMA Techline

By Timothy D. Stark Q: What is the difference between the strength parameters c and ø, and a and δ? A: Good question because these parameters are frequently used interchangeably. c and ø, and a and δ are shear strength parameters used to represent the strength/failure envel…
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