Biplanar and Triplanar Drainage Geonets

Biplanar and Triplanar Drainage Geonets consist of a high strength HDPE Geonet core with one or more layers of non-woven geotextile bonded to it. They are designed for in-plane flows over large surface areas. The biplanar and triplanar geonet core is UV stabilised with 2% carbon black and is chemically and biologically resistant. Available in 2m and 4m wide rolls with a 10cm fabric overlap, each batch is tested and quality certified. Biplanar and triplanar drainage geonets are also available without a geotextile.

Biplanar and Triplanar Drainage Geonets

Biplanar Geonets

Triplanar geogrid with geotextile Combigrid

Composite Triplanar Drainage Geonet


Biplanar Drainage Geonets have a low intensity but high elongation and are suited for projects where the foundation is reasonable or the bearing capability demand is low, such as parks, temporary roads, banks and slopes. Biplanar geonets can be used in place of soil drains in civil and environmental applications such as under-slab drainage, leak detection, gas venting, leachate collection and as additional protection for waterproofing membranes.

Properties CE111 CE121 CE131 CE131B CE151
Width (m) 2.5
Length (m) 50-100
Aperture (mm) 8-6 8-6 27-27 22-22 74-74
Tensile Strength >= (kN/m) 2.0 7.68 5.8 6.4 1.82
Elongation at maximum strain <= (%) 41.0 20.2 16.5 18.6 23.2
Tensile strength at 10% strain >= (kN/m) 1.32 6.80 5.20 5.74 3.83

Triplanar Drainage Geonets consist of two outer layers of inclined ribs separated by strong vertical ribs. Also known as combi geonets, the whole structure is bonded to a non woven geotextile. The high compressive strength resists crushing and the geotextile delivers a high flow rate under load while preventing soil particles blocking the drainage core. The top and bottom auxiliary ribs also reduce the depth the geotextile intrudes into the core.

Physical Properties Test Method Units Type Mark
Composition / / 3 ribs 3 ribs /
Polymer / / HDPE HDPE /
Additive / / Carbon black Carbon black /
Geometric Properties
Thickness V=20kPa ISO9863 mm 7.0 7.6 a
V=200kPa ISO9863 mm 6.5 7.0 a
Unit weight ISO9864 g/m2 >=1250 >=1550 a
Roll width / m 4.00 4.00 a
Roll length / m 25.0 25.0 a
Roll diameter / m 0.50 0.53 a
Technical Characteristic
Transmissivity water V=20kPa ISO12958 l/m/s 2.60 3.00 a,b,c,d,e
V=100kPa ISO12958 l/m/s 2.40 2.80 a,b,c,d,e
V=200kPa ISO12958 l/ms 2.20 2.60 a,b,c,d,e
V=500kPa ISO12958 l/ms 1.80 2.20 a,b,c,d,e
V=1000kPa ISO12958 l/ms 1.30 1.50 a,b,c,d,e
Tensile Strength (KN/M) ISO10319 KN/m 12 14 a,b,e
Elongation, % ISO10319 KN/m 20 20 a,b,e

a= representative value
b= longitudinal
c= 2mm HDPE condition of pad border
d= l/m/s= 1.0E-3 m2/s
e= transmissivity and tensile strength tested every 25000m2


Geonet Brochure

Triplanar and Triplanar Geonets

    Biplanar and Triplanar Geonets

Comments are closed.