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Leak location

October 1, 2011

From the GMA Techline RE: Leak location I have been reading though the GSI White Paper #8 regarding the CQA method. I am designing a reservoir that will be around 50ft deep and has many 2:1 sideslopes (uncovered 60-mil HDPE liner) that I would also need to test for leakage. It doesn’t seem that the …

Accelerated flow testing of geosynthetic drains

June 1, 2011

By Sam Allen Introduction Most planar geosynthetic drains consist of a polymeric core with or without a geotextile bonded to one or both sides. The core, whether used by itself or in association with a geotextile, forms the main fluid transmission medium. Synthetic cores used in North America typically take the form of geonets that, …

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‘Old-timer’ recalls the history of geomembrane interface strength tests (Part 3)

By Allan J. Breitenbach, P.E. Editor’s note: Part 1 of Allan Breitenbach’s treatise recalling geomembrane testing in days of yore appeared in the February/March issue of Geosynthetics and continued with Part 2 in the April/May issue. This concluding section continues with descriptions of factors that influence liner interface test strengths. -rb- Cohesion vs. no cohesion …

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‘Old-timer’ recalls the history of geomembrane interface strength tests (Part 2)

April 1, 2011

By Allan J. Breitenbach, P.E. Editor’s note: Author Breitenbach’s treatise recalling geomembrane testing in days of yore started with Part 1 in the February/March issue of Geosynthetics. He continues in Part 2 with an examination of several related factors that influenced liner interface test strengths. -rb- The next sections of this article present a general …

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‘Old-timer’ recalls the history of geomembrane interface strength tests (Part 1)

February 1, 2011

By Allan J. Breitenbach, P.E. Introduction I was fortunate enough to attend the interesting 9th International Conference on Geosynthetics (9ICG) in Guarujá, Brazil, in May 2010. During the last day of presentations there was a good discussion on large-scale, laboratory, direct-shear liner testing: Whether to clamp and restrain the liner sheet or allow it to …

Smallest piezometer now on market

December 13, 2010

Roctest Ltd., designer and manufacturer of high-precision sensors, has launched the FOP-MicroPZ, the smallest fiber-optic piezometer available in the market, according to a company press release. Piezometers measure pressure from pore-water or other fluids and are deployed in tunnels, embankments, excavations, dams, water repository sites and other civil engineering and industrial applications. The FOP-MicroPZ is …

Glen Raven lab certified for geotextile testing

November 12, 2010

Strata Systems, a division of Glen Raven Technical Fabrics (GRTF), announced in a November press release that GRTF had received certification to test geosynthetic fabrics from the Geosynthetic Accreditation Institute’s (GAI) Laboratory Accreditation Program. This certification makes Glen Raven’s laboratory in Glen Raven, N.C., one of about three dozen laboratories in the world that is …

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Test parameters

October 1, 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 …

Training and certification for geomembrane liner leak location surveyors

August 12, 2010

By Ian Peggs, Ph.D., P.E Introduction The benefits of performing geoelectric leak location or liner integrity surveys (LIS) as the final stage of geomembrane liner construction quality assurance are well established. In fact, the New York State Department of Environmental Conservation (NYS DEC) Division of Solid & Hazardous Materials (DSHM) is proposing regulatory changes to …

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Floating interface testing for direct shear

October 7, 2009

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 critical interface is not known. (Victoria, USA) Reply: The first test using …