The GMA Techline and its 5th set of 500 Q’s-&-A’s

April 1, 2014  |  Q&A: GMA Techline

By Bob and George Koerner Introduction The Geosynthetic Materials Association (GMA) Techline was launched in September 2004—now in its 10th year!—as a free worldwide service to answer questions involving the many aspects of geosynthetic materials. From the outset there were no constraint…
Road stabilizers

February 1, 2014  |  Q&A: GMA Techline

From the GMA Techline RE: Road stabilizers I’m doing research for a landscape architect, and I’m looking into products that reinforce the soil beneath paved roadways. So far, that has led me to a range of geotextile and geogrid systems. In this regard, geosyntheticsmagazine.com has been …
Monitoring moisture change?

October 1, 2013  |  Q&A: GMA Techline

From the GMA Techline RE: Monitoring moisture change? There is an opportunity to monitor an application of the enhanced barrier system at a [municipal] hazardous waste site … for which an extension is currently under construction. The consultant, contractor, client, and authority will be moni…
Carbon footprint of geosynthetics

October 1, 2013  |  Q&A: GMA Techline

From the GMA Techline RE: Carbon footprint of geosynthetics One of my students is working on the topic “of influence of geosynthetics on the reduction of carbon footprint of geosynthetics in pavement construction. We are unable to get any data on the energy required for producing typical geosy…
Critter control and membrane repair

June 1, 2013  |  News, Q&A: GMA Techline

From the GMA Techline RE: Critter control Have you ever heard of an instance where critters (groundhogs, for instance) dug through a geomembrane cap? [We have heard] stories about membrane repair in response to rats and groundhogs. The rats were trapped in a lined floodwall berm. The groundhogs are …
Plastic connections

February 1, 2013  |  Q&A: GMA Techline

From the GMA Techline RE: Reinforced geomembrane seams When we last spoke, I mentioned we were looking for a plastic connectlon to insert into concrete blocks. Currently, we use galvanized steel, but where sulphates are an issue we cannot do this. Can you recommend anything? (Chris | UK) Reply: Firs…
Geogrid lateral load

January 28, 2013  |  Q&A: GMA Techline

From the GMA Techline RE: Geogrid lateral load I have proposed a GRS wall to replace a cut fill failure. Our geotechnical division says it will not hold the lateral load of the surcharge of a car or truck. It will be 6 feet deep, 8 feet wide, and 90 feet long. We will excavate … <div><a href=…
MSE wall connection

June 1, 2012  |  Q&A: GMA Techline

From the GMA Techline RE: MSE wall connection? When an MSE (mechanically-stabilized earth) wall is constructed using geosynthetic reinforcement, how is it connected to precast concrete facing? Are metal tabs cast in the concrete or can a geosynthetic product be cast in the precast panel? If this con…
Peak friction values for textured HDPE

June 1, 2012  |  Q&A: GMA Techline

From the GMA Techline RE: Peak friction values for textured HDPE? I am currently in the design phase of a landfill cover system that I would like to design with rather long 3:1 slopes consisting of an HDPE liner and geocomposite drainage net atop the waste and under three feet of cover soil. I am &h…
GCL and HDPE questions

June 1, 2012  |  Q&A: GMA Techline

From the GMA Techline RE: Two questions Does a geosynthetic clay liner (GCL) form whales from gas or water pressure, the same way as with a flexible membrane liner (FML), or does gas or water under pressure pass upward through a GCL? When a high-density polyethylene (HDPE) pipe crushes—say, du…