Bentonite Cutoff Anchorage

February 1, 2024  |  Q&A: GMA Techline

Q: I have a bentonite cutoff wall containing a positive pressure inside and an overfill situation where the waste being capped will have perched water in the waste mass above the perimeter elevation. Do you have a recommendation for the perimeter connection detail for such a situation?
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Geomembrane formulation

February 1, 2024  |  Q&A: GMA Techline

Q: We are specifying HDPE geomembrane for a critical project and noticed that GRI-GM13 only requires endurance testing “per formulation.” What is the definition of formulation and can we obtain Kiwa certification for a geomembrane produced using a known formulation?
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Global/Slope Stability Analysis

February 1, 2024  |  Q&A: GMA Techline

Q: My question stems from the fact that (in my area) there still seems to be confusion over when a global/slope stability analysis is required and who is responsible. A contractor might ask for some budget pricing for retaining wall design. Generally, this is in regards to a segmental retaining wall…
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Resin Sampling

February 1, 2024  |  Q&A: GMA Techline

Q: Is there a standard definition of a “lot of resin.” 
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Ply-Adhesion Values For Triplanar Geocomposites

February 1, 2024  |  Q&A: GMA Techline

Q: Is there a minimum ply-adhesion value for a triplanar geocomposite? I ask this knowing that GRI-GN4  (Test Methods, Required Properties and Testing Frequency for Biplanar Geonets and Biplanar Geonet Composites) specification states a minimum of 1.0 pound/inch. 
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Drainage Geocomposite Applications

February 1, 2024  |  Q&A: GMA Techline

Q: Do you have any case history information where a geocomposite was used as an underdrain below flat-plate, upstream armoring on an embankment dam? Specifically, I am looking for any long-term performance information (good or bad) and how much of that system (if any) may have had to be replaced due…
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Crimping prefabricated vertical drains

October 1, 2023  |  Q&A: GMA Techline

Q: Can you enlighten me of any work related to the crimping of prefabricated vertical drains (PVD) as a result of soil consolidation and settlement of harbor sludge or dredge spoil? We are anticipating 3 feet (1 m) of settlement in 30 feet (10 m) of sediment (sludge/spoil).
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Geotextiles traceability

October 1, 2023  |  Q&A: GMA Techline

Q: We are having a problem with traceability on our project with geotextiles. Does this really matter for each roll and lot of material?
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Septic system drain fields

October 1, 2023  |  Q&A: GMA Techline

Q: Should I sock the perforated pipe of my septic system drain field and eliminate the gravel rock/bedding around the pipe?
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Service life of exposed geosynthetics

October 1, 2023  |  Q&A: GMA Techline

Q: Can we correlate laboratory versus outdoor weathering of geomembranes? I would appreciate your thoughts on this matter because we are getting technical challenges on this issue from regulators.
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