For decades Cofra has specialised in the supply and installation of geo-synthetics for civil engineering. The company has specifically concentrated on methods of soil improvement for the construction of infrastructure projects.

Through the execution of these projects Cofra has developed advanced installation techniques and equipment for each of the materials, with the equipment being operated by experienced and qualified personnel. Clients all over the world have profited form the experience Cofra has gained in the application of geo-synthetics.

 

Cofra’s initial expertise was in the manufacture, supply and installation of vertical drains, MebraDrain™ (PVDs, preformed vertical drains), also referred to as wick drains. These are the modern equivalent of sand drains and can be used in conjunction with surcharge. PVDs may be used in a variety of applications to accelerate the settlement in soils, to form a path for the extraction of gas and leachate.

 

The performance of MebraDrain™ may be enhanced by the application of a vacuum system to the drain. This system is called BeauDrains™, the vacuum in most instances is equivalent to 2.0m of surcharge. This may be cost effective in areas where procurement of surcharge fill is expensive or has a significant detrimental environmental effect. There is also the advantage of minimising the carbon footprint.

Cofra has extended its use of synthetics to include a piling system, AuGeo™, for the support of embankments across areas of poor quality soils. Therefore, forming a settlement free embankment, that may be used under car parks or similar where there is a uniformly distributed load to be supported. The system utilises the same installation methods as the PVDs.

Cofra’s knowledge in the use of geo-synthetics has helped develop vinyl sheet piling, Geoflex™, for use in retaining walls and as a hydraulic barrier in soils. Vinyl does not replace steel sheet piles in the heavier applications but will, subject to design, support wall up to 2.0m in height without ties. Cofra uses recycled plastics in the manufacture of Geoflex™, and continue to look for ways to increase the quantities of recycled materials within their projects without compromising either quality or design parameters.

Finally, Cofra offer Geolock™, an HDPE sheet inserted vertically into soil to form a water and gas barrier to contain contamination. This may be installed in a variety of ways – in soft soils with our PVD stitchers, by traditional trenching with a bentonite annulus, or in a 290mm wide trench with a 290mm bentonite annulus.