Landfill Gas Emissions Modeling

February 1, 2023  |  Q&A: GMA Techline

Q: I’m writing to see if you are aware of any research on landfill gas (LFG) emissions modeling through various geomembranes, particularly for temporary covers? 
Overlap seam specifications for geotextile separators

February 1, 2023  |  Q&A: GMA Techline

Q:What is the typical overlap for a geotextile used as a separator in a highway project?
Transitioning from 30 MIL PVC geomembrane to 60 MIL HDPE

February 1, 2023  |  Q&A: GMA Techline

Q:I have a client that operates a Subtitle C landfill that utilizes a double-liner system of 30 mil (0.76mm) PVC geomembrane for the base liner. They are wanting to evaluate the possibility to transition from 30 mil (0.76 mm) PVC to 60 mil (1.52 mm) high-density polyethylene (HDPE) geomembrane for t…
Strength Reduction Of Geogrids Used In Reinforced Walls

February 1, 2023  |  Q&A: GMA Techline

Q:At the moment there are two issues that create uncertainty with the use of PET fabrics and geogrids in the Netherlands. First, for many years we built pile-supported geosynthetic reinforced embankments (so-called piled mattresses to reduce settlements under embankments on soft soils). The fill is …
Geomembranes with better performance

February 1, 2023  |  Q&A: GMA Techline

Q:We are researching liner alternatives for an industrial client that will have lined impoundments subject to high temperature influent (>140 degrees F), low pH (1 SU+/-), and may have organic contaminants. Are there any polyethylene geomembranes that meet these requirements? 
Geogrid durability and cement

October 1, 2022  |  Q&A: GMA Techline

Q: I am searching for data or specifications pertaining to long-term degradation resistance of geogrid exposures to cement—more specifically, cement-treated soils. Your assistance would be greatly appreciated.
Underwater wick drain installation

October 1, 2022  |  Q&A: GMA Techline

Q:We have an underwater wick drain application in the Delaware River adjacent to the Delaware Memorial Bridge. S. T. Hudson Engineers Inc. is working with the Delaware River & Bay Authority (DRBA) on a ship collision protection system (SCPS) at the piers in the river. There is up to 50 feet (15 …
Designing Reinforced Soil Structures

October 1, 2022  |  Q&A: GMA Techline

Q: Why is strain compatibility important in designing reinforced soil walls?
Liner system leakage estimations

October 1, 2022  |  Q&A: GMA Techline

Q: What is the anticipated leakage rate through a composite liner (i.e., geomembrane on low-permeability soil) system?
Liner materials that can perform in the toughest applications

August 1, 2022  |  Q&A: GMA Techline

Q: I am working on a 60 mil (1.5 mm) high-density polyethylene (HDPE) that will receive septage leachate. The pH will be below 5 and probably lower. I am looking for technical literature on liner performance at pH levels possibly as low as 2. Thank you for your assistance.