What is piping control
Piping is a major failure mechanism in dikes. Conventional methods to counteract this issue – the construction of auxiliary berms, sheet piling or diaphragm walls, for example – have a huge financial and spatial impact.
Inserting a vertical, sand-proof geotextile barrier along a dike’s landside slope is a relatively simple, quick and sustainable solution for piping. While this geotextile is permeable for water, it does not let through sand grains. As a result, the ‘pipe’ developing under the landside slope is actually stopped in its tracks by the geotextile barrier.
Piping Control is an innovative method for vertically inserting geotextile in the inner berm of the dike in a one-pass operation. The system consists of a deep trenching machine that simultaneously feeds the geotextile and unfolds it below the surface. After this, the geotextile is immediately filled up along both sides with a mixture of sand and clay that matches the soil’s original composition:
The insertion of a vertical sand-proof geotextile barrier has numerous advantages over traditional methods. Once the textile has been inserted, it is hidden from sight – meaning that it does not affect existing landscape values. In addition, this solution does not use any extra space, as would be the case with an auxiliary berm.
One-pass method limits nuisance
In the Netherlands, many homes can be found near or adjacent to the local dike, and there is often limited space. Thanks to its clever design, the Piping Control system only needs a strip of 5 or 6 metres to work along. This low-impact method means that both land expropriation and building demolitions can be kept to a bare minimum. This swift and simple operation results in significantly less nuisance for people living on and near the project site.
The method can be applied any month of the year, apart from the (brief) period during which water extends to the high-water dike – when it would be ill advised (and indeed illegal) to work on the dike.
More economical than traditional methods
In addition, a geotextile barrier comes at a lower cost than traditional piping prevention methods. Considering that a total of 540 km of dikes do not satisfy the new calculation rules*, the expense involved in a traditional approach is truly staggering: an estimated 3 to 4 billion euros. With Piping Control, these upgrades can be done at half the cost.
35% lower CO₂ emissions
And finally, calculations show that compared to traditional methods, Piping Control yields CO₂ savings of 1,000 kg for every 100 metres of dike. This is an improvement of roughly 35%.