Grid zone backfill

June 1, 2011  |  Q&A: GMA Techline

From the GMA Techline RE: Backfill I know you indicated sand was the ideal grid zone backfill. I suppose crushed limestone has a high installation damage reduction factor due to its angular nature. But what about a rounded river gravel? We’re running out of ash as we near completion of an MSE …
The 15 most difficult GMA Techline questions from the 3rd 500 Q’s-and A’s

February 1, 2011  |  News, Q&A: GMA Techline

From the GMA Techline Note: This is an appendix to the article, “GMA Techline’s 3rd 500 Q’s-and-A’s.” Question 1 Q: I am trying to find a way to predict the size and shape of a gas bubble that might form under a geosynthetic liner in a pond lining system—specifically, the relatio…
GMA Techline’s 3rd 500 Q’s-and-A’s

February 1, 2011  |  News, Q&A: GMA Techline

From the GMA Techline Introduction The GMA Techline was initiated in September 2004, as a free worldwide service to answer questions involving the many aspects of geosynthetic materials. From the outset there were no constraints placed on the questioner or their questions. GMA contracted with the Ge…
GG3-87

October 1, 2010  |  News, Q&A: GMA Techline

From the GMA Techline RE: GG3-87 I was wondering if guideline GG3-87 is still in use. If it is, could I get a copy? Thank you. (Jason | Kentucky) Reply: Good question and, as with many other GRI Standards, we have given the GRI method to ASTM, which now has a replacement. The replacement for &hellip…
Geo mat for reinforcement when needed

October 1, 2010  |  Q&A: GMA Techline

From the GMA Techline RE: Reinforcement We have a dirt area at our recycling center that large trucks drive on and, during normal conditions, the soil is stable. However, problems arise after heavy rains and it becomes difficult for the trucks to drive on. So, we are looking for a “geo mat&rdq…
Walls and culverts

October 1, 2010  |  Q&A: GMA Techline

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…
Textured HDPE?

April 1, 2010  |  Q&A: GMA Techline

From the GMA Techline Subject: Textured HDPE? We are looking at a stormwater basin about 2-3 acres in size with a 20-30ft side slope at 4:1. We are using 60-ml HDPE smooth and it will be covered with sand. The pond will be partially filled with water most of the time. Will the sand stay … <di…
Difficult lining task

April 1, 2010  |  Q&A: GMA Techline

From the GMA Techline Subject: Lining task Please find attached some recent pictures of an aluminum storage tank in one of our ongoing projects. Initially, we proposed to line the tank with a 2mm-thick HDPE sheet based on its chemical resistance. The tank is already fabricated with carbon steel by o…
Veneer stability

April 1, 2010  |  Q&A: GMA Techline

From the GMA Techline Subject: Veneer stability I have a question about veneer stability in moving earth upslope vs. downslope. In the downslope equations in GRI18, how is the lack of a buttressed passive wedge accounted for in the factor of safety (FS) equations during placement of soil? I think I …
Questions about GM/GCL composite liners

April 1, 2010  |  Q&A: GMA Techline

From the GMA Techline Subject: 3 questions How do I approach designing/specifying GM/GCL composite liners for MSW landfills? Do I simply adopt the GM13 standard, which is based on fundamental research, and then double-check that the leachate leakage rate is within acceptable limits for my specific p…