To investigate "piping", a test dike was built specially, containing advanced monitoring equipment. The phenomenon was initiated in a controlled way, resulting in the collapse of the test dike. The experiment and the measurements show that piping is a failure mechanism that needs to be taken seriously.

When water levels are high, the resulting pressure can force water to seep through the base of a dike. This water may take grains of sand with it, creating tubular openings (pipes) under the dike that get bigger and bigger, endangering the stability of the structure. This can weaken the dike and, in the worst case, cause it to collapse. The Netherlands Safety Chart (VNK) study identified piping a few years ago as a potentially dangerous failure mechanism and recommended further research. The experiment at the Smart Dike location in Bellingwolde was the culmination of that research.

The experiment took place in a section 4 m deep, 40 m long and 25 m wide. The subsurface in the section consisted of sand. Over the width of the section, there was a dike with high water on one side (more than 2.5 m) and low water on the other (0.1 m). The measuring equipment installed in advance acquired data about water pressure and the deformation of the dike. And heat-sensitive cameras recorded the piping process.

The experiment was unique: this was the first time that the mechanism had been simulated and observed on this scale in a controlled setting. For the first time, it was also possible to demonstrate that there is a link between piping and the actual failure of a dike. After this first successful experiment, there will be another three.

Rijkswaterstaat is involved in the piping experiments through its SBW programme looking at water defences. The results of the experiments may result in changes to computer models for determining the strength of dikes, so that dike managers will probably be able to predict piping more accurately in the future.

The experiments took place at the smart dike location, an international testing ground for new inspection and monitoring technology for water defences. The smart dike gives the business sector, knowledge institutions and government authorities the opportunity to conduct full-scale experiments in controlled conditions that can contribute to improvements in inspection technology and the development of a generally practicable monitoring system for water defences.

The smart dike is an initiative of N.V. NOM, STOWA, Stichting IDL, Deltares and TNO. Staatsbosbeheer and the Hunze en Aa’s water authority are partners in smart dike projects. The following companies also participated in this experiment: Alert Solutions, Dike Survey, GTC Kappelmeyer, Intech, Inventec, Landustrie, Ten Cate and VW Telecom. The experiment was financed by Rijkswaterstaat and the Ministry for Economic Affairs, Pieken in de Delta and by the European Fund for Regional Development. In addition, the smart dike also participates in the Flood Control 2015 research programme, in which government and the corporate sector are working together to improve the supply of information during acute flood threats.