Part 1: Mechanisms governing the performance of unpaved roads incorporating geosynthetics

February 1, 2016

Authors’ note: Road improvement is one of the major applications of geosynthetics. It is also one of the most complex because of the variety of mechanisms involved. This Part 1 article provides a description of the mechanisms that govern the performance of unpaved roads incorporating geosynthetics. It will be followed, in the next issue of …

Geotextile question

We have a geotextile AOS requirement of 0.15mm for which we have recommended a 10-ounce geotextile to our client. Because our client has an abundance of 8-ounce geotextile on-site, he would prefer to make use of it in place of the recommended 10-ounce. My question to you is this: Can two layers of 8-ounce geotextile …

Renovating the Zhongsha Bridge

Award of Excellence Ace Geosynthetics Introduction The object of this renovation project is the Zhongsha Bridge located on the Zhuoshui River in west-central Taiwan. The 2,345m-long bridge spans the Zhuoshui on the border between Changhua and Yunlin counties. The bridge was built in 1978 with prestressed hollow core piles and prestressed beams. It is part …

January 2016 GMA News

Fall 2015 Lobby Day GMA hosted its 2015 fall lobby day in Washington, D.C., Oct. 29. This was an exciting time to be in our nation’s capitol as Rep. Paul Ryan (R-Wis.) was elected Speaker of the House and U.S. lawmakers were finally putting the finishing touches on a long-term transportation funding bill. The evening …

Geocomposite for landfill’s groundwater drainage layer

Background Dubuque Landfill Cell 9, Phase 2, is located in Dubuque, Iowa. The original liner system (from bottom up) consisted of 1ft (30cm) groundwater collection layer, 8oz/sy (270g/m²) separation geotextile, 1ft (30cm) earth barrier layer, 2ft (60cm) compacted clay layer, 60mil (1.5mm) high-density polyethylene (HDPE) liner, 8 oz/sy (270 g/m²) protection geotextile, and 1ft (30cm) …

Reinforcement deformations

You made a presentation in Peru where you talked about a new method to calculate deformations on reinforced embankments. Now I am working on a project where the foundation needs to be, in part, over consolidated tailings. Even though we are putting rockfill embedded on the tailings, our pseudo-static analyses result in a FS of …

MQA and GRI specs

There is much inconsistency regarding the definition of a production batch quantity for geomembranes and how this relates to MQA sampling frequencies. What is the intent of the GRI specifications? Maggie | Australia Maggie, Regarding MQC—the factory production of like material—the GRI specifications give the frequencies of each particular test. These values were the subject …

Comparison testing of geosynthetic drainage products

Unlike ASTM D6364 “Standard Test Method for Determining Short-Term Compression Behavior of Geosynthetics,” ASTM D1621 “Standard Test Method for Compressive Properties of Rigid Cellular Plastics” is a testing standard designed to measure the compressive properties of rigid cellular plastics (i.e., foam), not geocomposite drainage products. Unfortunately, the geosynthetic community has been saddled with this test …

LLDPE Question

“Burnout” occurred when the double-seam fusion welder got stuck as it welded (a stop at a small crease or at times going up a slope) followed by the welder sitting in one spot for a short time causing a burn hole in the LLDPE. The welder continues from that point onward once the situation is …

Breathable membrane

I am a graduate student pursuing a Ph.D. in environmental engineering. My project involves solving sanitation issues of urban slums in India using breathable membranes. We use a 55-gallon drum lined with this breathable membrane to serve as collection and storage for the fecal matter. We have been pursuing modifications on the project design and …