Geocomposite drainage layers

October 1, 2015  |  News, Q&A: GMA Techline

Flammability? Zip ties? MARV? Ponds? GT specs? Questions and answers from the GMA Techline. I wonder about your opinion on the use of a triplanar geocomposite for landfill drainage layer. We have not approved these in our jurisdiction to date. I have a current application where this is proposed to b…
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Saturated soil cover on liner question

October 1, 2015  |  News, Q&A: GMA Techline

Questions and answers from the GMA Techline. I need your advice on a reservoir we are designing. It is an irrigation reservoir with a 40-mil HDPE geomembrane liner on a 3:1 slope. The client wants to cover the liner with 1ft of silt loam soil. The water elevation in the reservoir will fluctuate abou…
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Geotextile data

October 1, 2015  |  News, Q&A: GMA Techline

Flammability? Zip ties? MARV? Ponds? GT specs? Questions and answers from the GMA Techline. I am a student of hydraulic structures and I need some data about transmissivity of geotextiles (ASTM D4716 or ISO/DIS 12958); and also permittivity or cross-plane permeability (ASTM D5493 or every valid stan…
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Protrusion/particle shape—geotextile cushions

October 1, 2015  |  News, Q&A: GMA Techline

Flammability? Zip ties? MARV? Ponds? GT specs? Questions and answers from the GMT Techline. Our landfill liner project specifications require the use of rounded to subangular gravel to be placed as a leachate drainage layer or leachate collection pipe bedding. The gravel is separated from the geomem…
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Zip-tie strength

October 1, 2015  |  News, Q&A: GMA Techline

Flammability? Zip ties? MARV? Ponds? GT specs? Questions and answers from the GMA Techline. We had a problem at one of the construction projects where we were providing CQA. It turned out that the installer had two different types (and apparently strengths) of zip ties. There ended up being seam fai…
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GRI White Paper #10/Test Method GTI2(A)

October 1, 2015  |  News, Q&A: GMA Techline

Flammability? Zip ties? MARV? Ponds? GT specs? Questions and answers from the GMA Techline. I have reviewed GRI White Paper #10, GRI Test Method GT12(a), ASTM D4354, and ASTM D4759 and have a question. I have reviewed some recent CQA test results of a nonwoven cushion geotextile roll sample and whil…
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Nonwoven needle-punched GT

October 1, 2015  |  News, Q&A: GMA Techline

We specify that the geotextile under riprap must be nonwoven, needle-punched, Class 1. NCHRP Report 568 (page C-25, Section 7.1) requires that nonwoven geotextile filter under riprap must have a mass density greater than 12osy (ounces per square yard). We have the following questions: What is the co…
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GMA is a sponsor for Educate the Educators

October 1, 2015  |  News

In late July, I joined representatives from seven GMA member companies to attend the revived Educate the Educators conference held at the University of Texas in Austin. The purpose of the event was to educate university professors from the United States and around the world on the benefits of geosyn…
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Educating the Educators on Geosynthetics

October 1, 2015  |  News

Wouldn’t it be great if graduating civil engineering students knew much more about geosynthetics? Frankly, it would be nice if they at least knew the difference between a geotextile and a geomembrane, wouldn’t it? Often, they don’t have the opportunity to study geosynthetics as part of their u…
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Drama in D.C.?

October 1, 2015  |  Editorial, News

One of my favorite trips every year is the Geosynthetic Materials Association (GMA) Fall Lobby Day. It is usually a good time to be in Washington … not too hot, not too cold, slight chance of rain. It is also the political season for dramatic action—or in recent sessions of Congress—inaction a…
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