Floating interface testing for direct shear

October 7, 2009  |  Features

From the GMA Techline Subject: Floating interface testing for direct shear Can you give us some guidance on the appropriateness of conducting geosynthetic direct shear testing using “floating” or multiple interfaces? It is our understanding that this method is typically used when the cri…
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A new sensible approach: Are we specifying action leakage rates or actionable leakage rates?

September 2, 2009  |  Features

By Glenn T. Darilek and Daren L. Laine Introduction The logical criteria for specifying an action leakage rate (ALR) is not whether a certain rate is achievable with good construction practices, but whether there is a practical solution if the ALR is not achieved. Specifying a low ALR can be a disas…
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History, development, and future prospects for geosynthetics industries in China (Part 1 of 2)

August 1, 2009  |  Features, News

By Jingkui Chi Editor’s note: Part 2 of this 2-part series ran in the October/November issue of Geosynthetics. Following the Abstract, Part 2 concludes with sections 3 and 4 of this manuscript. Abstract This article presents an introduction to the development of China’s geosynthetics pro…
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Research and innovation: Seismic performance of various geocell earth-retention systems

August 1, 2009  |  Features

By Dov Leshchinsky Editor’s note: Feature articles in Geosynthetics magazine focus on projects and how geosynthetic materials are used in a variety ofapplications. Very rarely is the focus solely on a specific product, company, or individual. Professor Leshchinsky and I note that this article&…
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IAGI certified welding technician course, Romanian style

August 1, 2009  |  Features

By Ian Peggs When I knew that Lyn and I were going to EuroGeo4 in Edinburgh (September 2008), we decided to take advantage of the cheap European airfares to spend a few vacation (What a concept!) days in Prague. Having already proctored an IAGI welder certification course for Permathene in New Zeala…
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Cohesion (or adhesion) and friction angle in direct shear tests

April 1, 2009  |  Features

A technical note regarding interpretation of cohesion (or adhesion) and friction angle in direct shear tests By Richard Thiel Introduction Direct shear testing with geosynthetics is generally performed in accordance with ASTM D5321, Standard Test Method for Determining the Coefficient of Soil to Geo…
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Ageing standard

April 1, 2009  |  Features

From the GMA Techline Subject: Standard needed — I need the standard GM11. We produce geomembranes and we will do testing but I do not have the ageing standard. (Yohana, Colombia) Reply: The GRI–GM11 Test Method has now been superseded by ASTM D7238 and ours has been discontinued. Please…
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GCL shrinkage: A possible solution

February 1, 2009  |  Features

By Richard Thiel and Chris Thiel Introduction A potential industry-wide concern for GCL shrinkage was identified by Thiel and Richardson (2005) at the January 2005 Geo-Frontiers conference in Austin, Texas, based on observed problems at several sites worldwide. All of the known problems were for ins…
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15-year test offers variances between EPS and XPS

February 1, 2009  |  Features

ACH Foam Technologies announced in December the completion of a 15-year test to determine water absorption characteristics of EPS (expanded polystyrene) and XPS (extruded polystyrene). The test revealed variances between the two materials in their resistance to water absorption. The test of below-gr…
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Researchers test sediment-scrubbing technology

October 1, 2008  |  Features

The testing was conducted at the Cocheco River in New Hampshire. By Beth Potier In a mud flat at the edge of the Cocheco River, just outside downtown Dover, N.H., scientists from the University of New Hampshire’s Contaminated Sediments Center are testing an innovative way to treat polluted sed…
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