Ermano de Almeida is currently working on the impact of waves on models of water defenses made of steel as part of the research for his PhD in the Hydraulic Engineering department at the Delft University of Technology. He studied Civil Engineering in Madrid and Aachen and obtained his master’s degree from TU Delft. When he got the chance to carry out the research project on flood defenses, he seized it with both hands. This was not only because he found the project interesting both theoretically and practically but also because managing and controlling water is one of the most important challenges in the coming decades.
De Almeida’s current research focuses on vertical steel and concrete hydraulic structures. Such structures can be found in ports and at locks and water outlets. They have also been used extensively in Dutch flood defenses along the coast of the North Sea. They are used there in combination with other hydraulic and mechanical installations to close the water outlets or waterways at high tide or during a storm surge. As a flood defense, this type of construction is particularly suitable for places where the opening of the gates for water flow and transportation are required, while also being able to remain closed and provide safety against flooding during storms.
The aim of the research project is to measure the strength of the impact that waves exert on vertical structures. These forces are particularly massive on vertical structures with an overhang because the strength of the wave cannot be diverted upwards. Furthermore, this also increases the pressure on the vertical portion of the structure. Additionally, the waves also exert an enormous force on the overhang. The overhang could be, for instance, a concrete protective edge above the flood defense or the ceiling of the opening from which partitions are suspended. According to De Almeida, investigating the effect of the resonance and vibration of the relatively thin metal plates under such load conditions on the service life of the structure and the material used is highly interesting.
“The number of situations in which such hydraulic structures has failed is not very high,” he explains, “but there are several cases known in which a lack of clear knowledge about the load characteristics and the structural response has led to unsafe conditions, and sometimes even to structural failure. By collecting more information about the power of the impact of waves, we are better able to make sturdy and safe structures without making them oversize as could be the case today. As a result, we save time, material and costs during construction. Perhaps we can even develop new ways of building this type of flood defense, based on the research.”