Two or three sets of crossing HDPE ribs, called biplanar or triplanar geonets, form channels that carry water or gas sideways under load. A geonet has no filtering ability of its own, so it is usually bonded to geotextiles to make a drainage composite. Its flow is measured as transmissivity under the normal load and gradient of the design.
Leak detection layer is geonet with fabric on both sides, and it has to run all the way up to the anchor trench.
Geonets carry water better along one direction than the other, so check that the flow direction on the roll runs downslope.
Also heard as
- drainage net
- biplanar geonet
- triplanar geonet
Related terms
Geocomposite
Product that combines two or more geosynthetics, most often a geonet core with geotextile bonded on one or both sides.
Transmissivity
In-plane flow capacity of a geosynthetic drainage layer per unit width, under a given gradient and normal load.
Leak detection layer
Drainage layer between the primary and secondary liners of a double liner that collects and reveals leakage.
Drainage
Carrying water along the plane of a geosynthetic to an outlet, as in wall backdrains and leak detection layers.