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…
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…
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…
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…
Effluent pond liners

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

Flammability? Zip ties? MARV? Ponds? GT specs? Questions and answers from the GMA Techline. I’m designing an effluent pond (the geotechnical aspect at least) and have a couple of questions: Do you see any issues with placing a gravel (rounded) subdrain system underneath the pond, sandwiched betwee…
GCL woven side against geomembrane

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

Flammability? Zip ties? MARV? Ponds? GT Specs? Questions and answers from the GMA Techline. I seem to recall a webinar or presentation in which the presenter warned against using the woven side of a GCL against a geomembrane due to bentonite squeeze-out and subsequent slippage. Instead, the nonwoven…
HDPE flammability

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

Flammability? Zip yies? MARV? Ponds? GT specs? Questions and answers from the GMA Techline. I am involved with a landfill permit renewal. A question keeps coming up concerning the flammability potential of HDPE liner. What is that potential and do you know of any liner system fires? Eric | USA Eric,…
Stormwater detention pond

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

Geomembrane testing? Root penetration? Welding HDPE with LLDPE? Woven geopipe? Questions and answers from the GMA Techline We are designing a campus that has a pond for stormwater detention, as well as an architectural/aesthetic pond that is about an acre in area, 6 feet deep, sideslopes 4H:1V, and …
Woven Geopipe?

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

Geomembrane testing? Root penetration? Welding HDPE with LLDPE? Woven geopipe? Questions and answers from the GMA Techline We hope you can give us contacts for some fabricators who could supply geosynthetic pipe or equal. We want to make woven pipe for water—sizes from 3 to 30 feet and pressures 1…
Welding on the slope

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

Geomembrane testing? Root penetration? Welding HDPE with LLDPE? Woven geopipe? Questions and answers from the GMA Techline I have a colleague who is insisting that we build a pond’s embankment extension by welding new geomembrane to an old one on the “slight” slope (really somewhere 1:4 ratio)…