Revetments are used in coastal and marine environments to protect the toes of coastal cliffs, bluffs and dunes, and to protect exposed land areas from erosion caused by waves, currents and tides. They may also serve other purposes such as reducing wave energy, limiting wave overtopping or wave reflection. TenCate Geosynthetics provides effective solutions with TenCate Polyfelt® F & TenCate Bidim® F ranges and Geotube® systems depending on the type of revetment being constructed. These systems include Geotube® units and geobag units for marine environments. For inland waterways or non-marine environments, sand filled mattress and concrete mattress systems are appropriate solutions.
Polyfelt® F & Bidim® F filters are used in coastal protection and stabilise the slopes of the dykes. Under rip-rap and other protection system, they maintain the fine soil layer in place.
Revetments may be constantly exposed to the water forces or they may be submerged. Submerged revetments are normally associated with beach and sand dune protection where the revetment is buried beneath the sand and hence out of sight. When storms occur, the sand may be eroded away from the face of the revetment, but its presence then prevents any further sand erosion. After the storm activity, the sand cover is replenished by natural or artificial means, and the revetment is submerged again.
Depending on the required height of the revetment, multiple units of Geotube® may be stacked to a required slope angle. To prevent scour at the toe of the Geotube® revetment, and consequent undermining, a scour apron can be installed prior to filling of the Geotube® unit. Geobags are also used for revetments and are sand-filled to maximum density on site and then pattern-placed to provide maximum revetment stability. Geobag revetments can be exposed or submerged. In instances of port and harbour constructions where wave energy is limited, the concrete mattress system can be used as a revetment and scour protection to replace concrete slabs, blocks and rip-rap alternatives.