Design Study on the Feasibility of a Self-closing Flood Barrier

Abstract

Flood risks and its consequences become more and more challenging and are demanding for the currently present dike systems and hydraulic structures in the Netherlands. This automatically raises the question for the possibility of adjustable temporary deployable flood defences that work autonomously. Nowadays it is more likely that a standard earthen dike will not be possible everywhere, due to site-specific characteristics such as available space or protected townscape. At these specific locations, a self-closing flood barrier can offer a solution, in view of minimally affecting the spatial quality with a reliable solution. The goal of this design study is to gain insight in the feasibility of applying a self-closing flood barrier in areas where spatial quality plays an important role and where the hydraulic boundary conditions demand for heavier structures. With the increase of densely built areas nowadays, the concept of an autonomously closing barrier is promising and an interesting alternative to consider.
In this thesis the objective is to develop a customised design of an adaptive self-closing flood barrier in the upper river region of the Netherlands. The city of Arcen in this case study is characterised by its cultural-historical values and its strong connection to the Meuse. This makes it difficult to construct conventional earthen dikes.
For the design purpose software with statistical data such as Hydra-NL is used to provide site characteristics, hydraulic and geotechnical boundary conditions and literature for information on currently applied barrier types and drive mechanisms. Furthermore, the design process has been completed with the help of the Design Guide Hydraulic Structures of Rijkswaterstaat and the Eurocode, from which a design originated in which stability and strength requirements have been met. The design resulted in a floating flat barrier of steel, which does not involve a complex design and is in line with integrating the structure in the area with minimal hindrance. In the design the focus lies on the functionality and the structural integrity with an in-depth look at adaptability and integrability.
The result shows that the design of a floating flat barrier is feasible as a self-closing structure in the city of Arcen. However, because of the location of the structure with the requirement of no townscape obstructing elements, a heavy support structure is needed for a design water level of 2.5 m above the ground surface. Furthermore, the applied boundary conditions leads to a large floater, even though the structure is slender. In order to develop a complete design, it is recommended to make a detailed design on the concrete foundation, to do a cost analysis on the construction and materials and investigate how a certain structure is received by the residents of Arcen. This will gain insight in areas to optimise the design furthermore.