Testing HDPE geomembrane liners

April 1, 2010  |  Products

From the GMA Techline Subject: Testing We prepared specifications for [a landfill] liner section that included parameters for nondestructive testing of the primary (80-mil) and secondary (60-mil) HDPE geomembrane liner. At this time, there is a need to install a 30-mil liner along the sideslope. It …
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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 …
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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…
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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…
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Geocell application

April 1, 2010  |  Products

From the GMA Techline Subject: Geocell application I would like to know the suitability of geocell as slope surface protection on acidic soil conditions. Can we apply geocell directly on top of the slope surface? (Azilah, Malaysia) Reply: Geocells are regularly used in exactly the type of applicatio…
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Welding LLDPE/HDPE

April 1, 2010  |  Products

From the GMA Techline Subject: Welding LLDPE/HDPE How do you achieve a satisfactory extrusion weld between a 1mm LLDPE geomembrane and a 2mm HDPE geomembrane? What constitutes a satisfactory extrusion weld? (Niall, Ireland) Reply: You have two things going against you in your situation: thickness di…
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What do you want from your green roof?

April 1, 2010  |  Case Studies

All green roofs include multiple underlayers of materials that, together, protect the building and provide the conditions for the top-layer plantings to thrive. Chief among these layers are geosynthetic materials required for separation, waterproofing, and drainage. This article includes selections …
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Strong as silk: Using a bio-enabled approach to produce nanoparticle composites

April 1, 2010  |  Features, News

By John Toon Using thin films of silk as templates, researchers have incorporated inorganic nanoparticles that join with the silk to form strong and flexible composite structures that have unusual optical and mechanical properties. This bio-enabled, surface-mediated approach mimics the growth and as…
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Geotextile tubes are integral components for oil-pipe foundations, erosion control

April 1, 2010  |  Case Studies

PEMEX marine facilities in Tabasco, Mexico. By Alfonso Solís, Amy Tang, and Zoe Lin Abstract In this project, geotextile tube technology is adopted as part of an integral solution for beach erosion problems at the Dos Bocas marine facilities for Petroleos Mexicanos (PEMEX). The solutions desi…
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New round-strand innovation in biplanar geonet structure

April 1, 2010  |  Products

An example of a solution to the problem of high-stress rollover for biplanar geonets. By Dhani Narejo and Mengjia Li Background The primary design property of drainage geocomposites is flow rate or transmissivity, which is measured in the laboratory according to ASTM D4716. The laboratory value is u…
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