Piping is a major failure mechanism in dykes, in which water seeps through an embankment, dyke or other engineering structure as a result of a huge difference in the level of the water on either side. The flow of water under the dyke may be so great that sand boils that carry along sand particles occur on the polder side of the dyke. Because sand is carried along with the flow, ‘pipes' – tubular openings – are created under the dyke that may cause it to burst. Vertical sand-tight geotextile is an innovative preventive measure used to avert piping. Together with Deltares, the Department of Waterways & Public Works in the Netherlands, TenCate Geosynthetics and others, the Rivierenland Water Board has developed and tested this vertical sand-tight geotextile.
The protective principle of the vertical sand-tight geotextile is based on the fact that the geotextile filter allows water, but not sand, to pass through. A pipe which develops on the polder side is stopped by the geotextile, thus ensuring that the sand remains trapped under the dyke and that piping cannot occur. This solid solution is not dependent on a minimum requirement for seepage length. The innovative technique was derived from TenCate Geotube technology.
Moreover, by combining this geotextile preventive measure with TenCate GeoDetect technology, the functionality of the filter is combined with sensors, which monitor the stability of the dyke. Both vertical sand-tight geotextile and TenCate GeoDetect are solutions which, due to the small amount of space they occupy, will increase both the feasibility of dyke improvement and cost effectiveness. In principle geotextile solutions for water management have a low carbon footprint. They are sustainable and durable alternatives to traditional solutions used in dyke improvement and land reclamation.
TenCate Geosynthetics develops and produces synthetic fabrics, nonwovens, wovens and geogrids, and creates design solutions and systems for infrastructure and civil technology. It has factories in Europe, North America and Asia.