A perimeter anchor trench termination is typically used at the top of an excavations slope or location that geomembrane needs to be secured to prevent slippage of the geomembrane.
Standard anchor trench excavation is 1.5’ wide x 1.5’ deep and offset 2′ back from the top of the slope though actual dimensions and depth are determined by project design. Sandbags placed in the anchor trench act as a temporary ballast to secure the geomembrane in place during installation and prior to backfilling.
Backfilling of the anchor trench can occur once the geomembrane has been fully installed as a system.
Geomembrane systems that will be left exposed require ballast shortly after install which can be permanent liquid on the geomembrane, bags, a system of ballast tubes, or other approved method.
Backfill covered geomembrane systems require soil placement as soon as the geomembrane is fully accepted; soil placement needs to follow design engineer and standard geomembrane cover soil placement techniques to avoid damage to the system.