The solution for strong levees and dry feet

The family business  Van den Herik is a hydraulic engineer at heart. The passion for working with water arose in 1945, when large parts of Rotterdam's harbors had been destroyed. Founder, Jan Hendrik van den Herik, worked as a bricklayer on the reconstruction. The company has since grown into a multi-disciplinary enterprise, strong in both hydraulic engineering projects and the detection of conventional explosives. Van den Herik is characterized by versatility, a sustainable approach and its innovative capacity. One of its innovations is piping control.

A major problem is the dike safety of rivers; in the coming years we have a huge dike reinforcement assignment for an expected 1,900 kilometers of dikes. One of the major causes of dike insecurity is piping. Water seeps under the dike, taking sand with it, weakening the dike and causing it to collapse. The good news is that there is a solution, which is the application of vertical sand-tight geotextile. "In 2013, the Rivierenland Water Board came with the request to develop a method for applying this geotextile," says Jeroen Terlingen, manager of project support departments. "Our idea for developing one possible application technique came out on top: Piping Control. This is an in-house developed, innovative method to apply the geotextile vertically in the toe of the dike and thus stop piping."

Deep in the ground

To apply the material, Van den Herik uses a deep milling machine. On this machine they have built a module about 3.5 meters high that can apply the geotextile deep into the ground. This with comparatively very little environmental inconvenience. "The deep milling machine unfolds the fabric underground where the fabric is immediately backfilled on both sides with sand and clay according to the original structure of the soil. We can apply 350 meters per day with this. The relevant part of the dike is immediately sealed. This gives important advantages over traditional methods. First, it is no longer visible; secondly, there is no additional space requirement, which is the case when constructing an additional berm."

The Hopper Dredger (TSHD) Charlock, certified as a clean ship, in action off the Bloemendaal coast.

More sustainable and economical

Research by six water boards shows that there alone about 540 km of the more than 940 km of dike examined are insufficiently resistant to the failure mechanism piping. Piping Control has more advantages. In practice, it turns out to be more economical than traditional methods. "If we look at the 540 km of dike from the study mentioned, the costs of applying traditional solutions are very high. Estimated three to four billion euros. With Piping Control, the costs can be halved. In addition, Piping Control delivers a CO₂-savings of 1,000 kg for every 100 m of dike. That is a saving of about 35% of CO₂."

Tip of the iceberg

The method has now proven itself in practice at Rijswijk and Ingen as well as on the LiveDijk of the Willemspolder. It was recently applied in the Twente Canal dike improvement project where the system has been further developed so that the geotextile can now also be connected to engineering structures in a sand-tight manner and endless lengths of geotextile can be applied without interruption. In addition, we now have a monitoring system that can show for every meter of Piping Control installed that it was installed in accordance with the requirements.  In short, it is the solution for safe dikes and dry feet, where there are also plenty of opportunities abroad to apply Piping Control as a preventive measure.   

Van den Herik

Industrieweg 24, 3361 HJ Sliedrecht

T +31 184 41 28 81

E sliedrecht@herik.nl

www.herik.nl