GNA Special Bulletin – Developments in Monitoring of Geomembrane and Geosynthetics
In this GNA Special Feature we introduce Smart Geosynthetics based on LIMS, FOS and LLL technologies.
TenCate GeoDetect™ – Fiber Optic Sensing (FOS) Geosynthetics
Ten Cate GeoDetect is Fibre Optic Technology (FOT) Built Into Geosynthetics
Fiber Bragg gratings (FBG), Stimulated Brillouin Scattering and Raman Scattering are all proven fiber optic technologies that can be built into TenCate GeoDetect. These technologies measure strain, strain & temperature or temperature only changes in soil structures.
Strain as low as 0.02% can be measured with a spatial resolution of 1 m.
With the proper software, changes in temperature can be monitored at 0.1 deg.C with a spatial resolution of 1 m.
https://www.environmental-expert.com/products/tencate-geodetect-fiber-optic-sensing-geosynthetics-532772
See Close-Up Photograph of TenCate GeoDetect™ – Fiber Optic Sensing Geosynthetics
http://www.tencate.com/emea/Images/BG-GeoDetect28-17137.jpg
Conductive Geomembranes for Fast Leak Detection; Leak Location Liner (LLL)
As J. P. Giroud famously said “all liners leak”.
An accidentally dropped tool, an oversized rock, or machinery used to place cover material can cause tears or holes in the geomembrane.
http://www.jpgiroud.com/statements-of-qualifications/liner-systems/
Research has shown that the most effective way to detect leaks is by using Electrical Liner Integrity (ELI) surveys.
The Spark testing method is used on exposed applications and the dipole method is used once the liner is covered with soil or water.
According to a landfill leakage and quality assurance study (Beck, 2012), if no geoelectric survey is performed, there is a 22.2% probability of exceeding the action leakage rate (ALR), and only a 7.1% probability exists if the Dipole Method is used.
However, if both an exposed geomembrane test and a Dipole survey are performed, the probability is reduced to 0.00001%.
A Leak Location Liner is a high performance geomembrane with a co-extruded, electrically conductive bottom layer. With Leak Location Liner, Spark and Dipole surveys can be conducted on both exposed and covered applications, helping to reduce the probability of exceeding the specified Action Leakage Rate (ALR). The conductive layer makes it possible to detect leaks on wrinkles and other non-conductive surfaces, and it allows the liner to be retested as often as necessary, even after cover materials have been placed.
http://www.gseworld.com/Products/Geomembranes/Leak-Location/
GSE Liner Integrity Monitoring System (LIMS)
GSE & Texplor CombiModules™ can be welded directly onto HDPE liners.
Incorporating a Central Monitoring Unit, the system works by measuring the electrical fields above and below the geomembrane.
If the liner is damaged, the system detects a change in the electrical field and signals a leak.
This process is repeated in cycles to continuously monitor the site and provide real-time information to the operator.
http://www.gseworld.com/content/documents/brochures/Liner_Integrity_Monitoring_System_Brochure-Small.pdf
GNA Special Bulletins communicate ground breaking advances and technologies in the geosynthetic area.
GNB™ – Geosynthetic News Bulletin™
GNS™ – Geosynthetic News Special™
GNF™ – Geosynthetic News Feature™
are tradenames of the Geosynthetic News Agency and Geosynthetic News Alerts (GNA)