The Geosynthetic Materials Association (GMA) offers the GMA Techline, a resource for technical questions about geosynthetics. E-mail: gmatechline@ifai.com for fast, free, direct answers to your technical questions.
GMA serves as the central resource for information regarding geosynthetics and provides a forum for consistent and accurate information to increase the acceptance, and to promote the correct use, of geosynthetics.
Browse the entries below list to find past answers highlighted in Geosynthetics magazine.
A reader needs some assistance in comparing two geosynthetic clay liners for a project.
Reader seeks geosynthetic fabric webbing or netting to be draped and sprayed with concrete.
Destructive tests are indeed taken on both wedge and extrusion seams.
A reader is designing a reservoir that will be around 50ft deep and has many 2:1 sideslopes.
A reader is designing a surface impoundment with interior side slopes of 1.5H:1V.
A reader has some air pockets under the geomembrane as the pond fills with water.
There are many exhumed site papers (such as Valcros) in the literature on geotextiles.
Historically, generic specifiers have stayed away from stipulating weight of fabrics.
The elongation rate for HDPE should be 2.0ipm and for LLDPE it should be 20.0ipm.
I am quite sure that there is nothing available on geomembrane to chipped tires but I suspect that the shear strength would be quite high.
The way a manufacturer would make such a thick fabric is to needlepunch each thinner layer and then do a secondary needling to put the multiple layers together.
The GMA Techline was initiated in September 2004 as a free worldwide service.
Bob Koerner ranks the 15 most difficult GMA Techline questions from the 3rd 500 Q’s-and A’s.
The Purpose of Drainage for Green Roofs
The Purpose of Filter for Green Roofs
Filter Components
For retention:
For permeability:
What are Geocomposite Drains?
Source: “How to Design Green Roofs & Landscapes” presented at the 2009 IFAI Expo, Sept. 22, 2009, in San Diego, hosted by the Geosynthetic Materials Association (GMA)