A video made by a resident of the Ringdijk Amsterdam dike reinforcement project:
In order to be well prepared for more extreme high water in the future, the Ringdijk in Amsterdam's Watergraafsmeer district must be reinforced. The dike is high enough, but not strong enough. The reinforcement is not done in a traditional way, but with so-called dike stabilizers.
This reinforces the dike from the inside and nails it to the subsoil. This allows the dike to keep its existing shape, it does not have to be widened or raised and the trees can remain on it. The technique is being used for the first time in a real, water-resistant dike. Many weaker dikes in the Netherlands are likely to benefit from nailing them to the subsoil. That is why this innovation is fully funded by the national High Water Protection Program (HWBP), which will strengthen more than 1,100 kilometers of dikes throughout the Netherlands in the coming years.
The project
The Ringdijk is located on the south side of the Ring canal in Amsterdam. The section between Wibautstraat and Middenweg must be reinforced. After this dyke reinforcement, the Ringdijk will protect the residents in the Watergraafsmeer for years to come against extreme high water.
Martin Schepers, program leader POVM: "Putting innovations into practice needs care: we sometimes don't know everythingbefore we start. But the 'task' that an innovation like this has in the barrier safety system, and the possibilities offered by monitoring to see and understand how strength increases in the subsurface, should give confidence for sustainable application."
The technique
The dike stabilizers, plastic anchor elements, are inserted obliquely into the dike where the extra force is needed. The force of in the dike is monitored twice daily. This is done by linking sensors to a total work force system through Vodafone data technology NB-iot. A total of 700 stabilizers will be installed in the dike. The installation is done with relatively light equipment and has less impact on the environment than piling or vibrating sheet piling or retaining berms. For the surrounding area, it results in less inconvenience. The project, commissioned by Waternet and carried out by JLD Contracting, will be completed in February 2019.
Working together for a safer Netherlands
The implementation of this innovative dike reinforcement project is funded by the national High Water Protection Program (HWBP), a collaboration between Rijkswaterstaat and the water boards. In the coming years, the HWBP will be responsible for the largest dike reinforcement operation ever. More than 1,100 kilometers of dikes and 486 locks and pumping stations must be tackled until 2028. Spread over almost 300 projects throughout the Netherlands, along the coast, large rivers and lakes. The HWBP allocates 7.4 billion euros for this dike reinforcement operation. We are constantly investigating how dike reinforcement can be done better, faster and cheaper. This is done within project-transcending exploratory studies (POVs). Within the POV Macrostability, one of the POVs of the HWBP, market parties, knowledge institutes and government authorities investigate and test solutions for the macro-stability failure mechanism. These include new calculation methods and techniques, such as dike nailing and vacuum consolidation.
For Zeeland dikes, a new way of reinforcing with pins is an option in the future. So says expert Martin Schepers. However, the technique being used for the first time in Amsterdam must first be testedfurther.
The idea of working with a kind of anchors is not new, the application in dikes is. It is faster than conventional dike reinforcement, farvar link = document.getElementById(‘link2736’);link.onclick = function(){document.location = link.getAttribute(‘href’);} oorzaakt minder overlast en is bovendien goedkoper.
The trial will start next week and is part of the studies ahead of the High Water Protection Program HWBP. In the so-called POV Macrostability, water boards, Rijkswaterstaat and knowledge institutions are working together to find smarter, and cheaper measures to reinforce the planned 110o kilometers of dike within the High Water Protection Program.
The dike stabilizer is a variant of the folding anchor that JLD from Edam has been marketing for more than ten years. It is already widely used to keep construction pits and sheet pile structures open. The anchor does not work with a grout plug, but with a steel foot that flips over when the tie rod is pulled. Almost like a ship's anchor, but deep in the ground instead of at the bottom of a waterway.
Three years back, a practical trial was already successfully conducted in Purmerend with the stabilizer, which is mainly intended to provide inward stability. With light equipment, the anchor is pushed with the tip downwards right through the potential slip circle. The anchor is flexible and can follow shrinkage and swell movements of the dike body.
Dhe Ring dike has been a point of contention for years. The trees on the dike would have to be cut down to keep the dike safe. Local residents were vehemently opposed to this. Eventually, both residents and the district agreed that as many trees as possible should be spared.
A new technique is now being used to strengthen the dike. With the "JLD dike stabilizer," the dike can be strengthened from the inside. The dike is nailed to the subsoil, as it were. This makes the dike safe again and the trees on the Ringdijk can be preserved. Work has started and will be completed in February 2019.
Read the original article here.