Geotextile under articulated systems in slope armoring

June 1, 2021  |  Q&A: GMA Techline

Q: I have a question about the geotextile placed under articulated systems in slope armoring. Based on my understanding, a drainage layer is recommended between the geotextile and the armoring structure, but, since the armoring structure has some spaces in between the armoring blocks, won’t the pa…
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Industry standard for wall drainage systems?

June 1, 2021  |  Q&A: GMA Techline

Q: I just watched your recorded video of mechanically stabilized earth (MSE) wall inspection. Thank you for the presentation; it was very informative. I do have a follow-up question for you. I was recently the site engineer for a precast panel MSE wall and now have the opportunity to inspect constru…
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GCLs in cold temperatures

June 1, 2021  |  Q&A: GMA Techline

Q: I am working on supporting a guide (independent) on what to consider when geosynthetic clay liners (GCLs) are installed in minus temperature regions (e.g., –4˚F [–20˚C]). There is not much published on this, especially independently.
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Useful service life of nonwoven geosynthetics

June 1, 2021  |  Q&A: GMA Techline

Q: Where can I find literature on the useful service life of nonwoven geosynthetic fabrics installed in soils? Thank you.
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Anchors, tie-rods and whalers

April 1, 2021  |  Q&A: GMA Techline

Q: We are having issues related to obstructions in the reinforced zone of our mechanically stabilized earth (MSE) retaining walls. In the first case, there is a rock outcrop that is limiting the length of the geogrid reinforcement. In the second case, we have a drop-down inlet structure to divert st…
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Geomembranes for reinforcement?

April 1, 2021  |  Q&A: GMA Techline

Q: We are using Robert Koerner’s Designing with Geosynthetics to calculate the required thickness of a geomembrane.
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Installing a geomembrane low to high gradient?

April 1, 2021  |  Q&A: GMA Techline

Q: We are a large liner installation firm that has been asked to install a geomembrane liner from low gradient to high gradient. Is this the new normal?
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GRI-GM19 peel specification

April 1, 2021  |  Q&A: GMA Techline

Q: Our liner system is a double composite and along a western tie-in. We need to extrusion-weld the secondary 60-mil (1.5-mm) HDPE (new cell) to an existing secondary 40-mil (1-mm) HDPE (old cell), and the state is continuing to have issues with the fact that we are using the 40-mil (1-mm) GRI-GM19 …
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Concrete interlayers

April 1, 2021  |  Q&A: GMA Techline

Q: We are interested in using a geotextile as an “unbonded concrete interlayer” over existing concrete pavement to float the new slab over deteriorated pavement, instead of a thin asphalt layer. Do you have any guidance for us in this regard?
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The GMA Techline

February 1, 2021  |  Q&A: GMA Techline

Moderated by George R. Koerner BIOLOGICAL DEGRADATION OF PE AND PP Q: Can you please enlighten me on the biological degradation of polyolefin polyethylene (PE) and polypropylene (PP)? A: Within the various plant forms of biological life, i.e., bacteria, actinomycetes, fungi and algae, polymer degra…
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