Use of geogrids in piggyback landfills

June 1, 2014  |  Q&A: GMA Techline

From the GMA Techline Do you have any specific project information on the use of geogrids in constructing piggyback landfills, especially in cold climates? I am interested in examples of the use and evaluation of geogrids when building landfills over closed landfills. Any information you can provide…
Seepage through geosynthetic-tube dam

June 1, 2014  |  Q&A: GMA Techline

From the GMA Techline I am trying to determine the steady-state seepage through a stack of sand-filled geosynthetic tubes with a triangular cross section (4-3-2-1 tubes). The permeabilities of the sand and the tube material are known. Can you suggest places I should look to get information on how to…
Minimum low temperature for dual hot-wedge seaming

June 1, 2014  |  Q&A: GMA Techline

From the GMA Techline Does the Geosynthetic Research Institute (GRI) offer any guidance on the minimum allowable ambient temperature to perform double-track fusion welds of HDPE and LLDPE geomembranes? (Jonathan | South Carolina) Reply: We have GRI-GM9 Standard Practice “Cold Weather Seaming o…
GM19, Revision 7—Peel separation 5 out of 5?

June 1, 2014  |  News

From the GMA Techline I am looking for a discussion of how peel separation % in the latest revision of GM19 went from 4 out of 5 specimens to 5 out of 5 specimens having to pass the 25% or less requirement. (Gabriel | California) Reply: Others have noticed it as well and in response … <div><a…
FS for anchor trench calculations?

June 1, 2014  |  News

From the GMA Techline Do you have a recommendation for what Factor of Safety to apply to the allowable geomembrane force for anchor trench calculations? (Melanie | Colorado) Reply: Over the years my thoughts have changed from having a high FS for geomembranes in their anchor trenches to treating the…
Geomembranes for pipes?

June 1, 2014  |  News

From the GMA Techline I have been asked to wrap a proposed 30-in. circular/cylindrical sanitary sewer pipe (HDPE) with a geomembrane as a dual containment layer. Could I get some pointers as to what kind of geomembrane(material, thickness, etc.) can be used to achieve this task? Any other informatio…