GRI GM13

October 1st, 2010

From the GMA Techline RE: GM13 We request you to kindly send us the GRI-approved grades for manufacturing HDPE geomembrane as per GM13. (Dilip | India) Reply: The GRI GM13 specification is a template of required properties for a manufacturer to meet or exceed. If your geomembrane does indeed meet the requirements, you can say […]

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Test parameters

October 1st, 2010

From the GMA Techline RE: Test parameters Most of the tests based on ASTM geotextiles provide for conditions of temperature and specific humidity. Do these parameters greatly influence the test results if you change or vary? Thanks, (José | Mexico) Reply: I believe that all of the standard test methods require controlled temperature and humidity […]

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Friction angle

October 1st, 2010

From the GMA Techline RE: Friction angle What sort of phi (interface friction angle) would you expect between #57 crushed limestone gravel (0.5in.–1.5in.) and a textured HDPE membrane? Surely more than 10 degrees, right? What would a conservative estimate be, I wonder? (Brian | Kentucky) Reply: It would be more on the order of 25–30 […]

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Walls and culverts

October 1st, 2010

GMA techline answers from Bob Koerner RE: Walls and culverts What, if anything, do wall contractors typically do to attach their wall to concrete culverts that intersect the face of an MSE wall? In this instance, we’re dealing with rock-filled baskets on the face. (Cole | Idaho) Reply: You ask a very contentious question. To […]

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