New technique to reinforce dykes in built-up areas

The Netherlands is working on the largest dyke reinforcement operation ever since the Delta Works: the Flood Protection Programme (HWBP).

More than 1,500 kilometres of dykes will be reinforced over the next 30 years with high ambitions for sustainability and innovation.

To meet this challenge, market players and water boards will have to cooperate. Project Strong Lek Dyke made it possible to investigate the Mixed-In-Place (MIP) method.

Van Oord and HITEC Road have partnered to further develop the MIP method, a technique to reinforce dykes in built-up areas in an efficient and sustainable way.

Unlike the usual methods for dyke reinforcement, the MIP method allows a dyke to be reinforced without expanding it. A fantastic solution for a country where space is scarce and where, for example, homes, farms and historical buildings are close to the dykes.

The MIP method is a technique where a milling cutter is used to create a wall in the dyke to a depth of 15 metres below the surface. This wall consists of a mixture of existing soil and binder, such as cement and water.

This wall reinforces the dyke in two ways. First, the wall prevents the formation of channels under the dyke that might carry sand particles and therefore weaken the dyke: piping as it is called.

Secondly, the wall stabilises the ground, preventing shifting or subsidence of the dyke. Because the existing foundation can be incorporated into the wall, this method is more efficient and sustainable than many other existing techniques such as installing steel sheet piling.

To learn more about the method, Strong Lek Dyke and the partnership please visit Van Oord website.