Geocomposite drainage layers

Flammability? Zip ties? MARV? Ponds? GT specs?
Questions and answers from the GMA Techline.

I wonder about your opinion on the use of a triplanar geocomposite for landfill drainage layer. We have not approved these in our jurisdiction to date.

I have a current application where this is proposed to be used (vertical expansion). I have concerns with the long-term performance of this product. There is uncertainty even with assigning reduction factors for flow.

I looked at the GSI website, but there aren’t any white papers or info that I could find. Could you perhaps let me know what your opinions are? Any research that you are aware of?

Thank you for any assistance.

Lydia | USA

Lydia,

Triplanar geonets are made from HDPE with a similar density as the biplanar types. I don’t know about the antioxidants since that is a manufacturing issue. The short time compression behavior is better than biplanar since there is no rollover of the large central ribs. Also the intrusion of the covering geotextile(s) is lower since the apertures are smaller.

One important consideration is that the triplanar geonets must be field placed with the central ribs parallel to the maximum slope gradient within different locations of the cell. Installation must be carefully controlled.

Bob Koerner | GMA Techline