Recent experimental and numerical studies have significantly improved the understanding of hydrodynamic forces exerted by dam-break flows on buildings. A first experimental campaign successfully validated a numerical model and provided key insights into flow dynamics, highlighting the methods to accurately estimate these forces. Building on this foundation, the present study investigates the influence of additional upstream obstacles on the forces exerted on a target building. The presence of obstacles can induce two contrasting effects: a shadowing effect, where the upstream obstacle reduces the force by deviating the flow and dissipating flow energy, and a flow acceleration effect, where flow deviation around the obstacle intensifies the impact on the target structure. To systematically explore these effects, a second experimental campaign was conducted, consisting of 62 different obstacle configurations. These configurations vary in terms of position, size, porosity, and flow conditions, allowing for a comprehensive assessment of their impact on hydrodynamic loading. A selection of these 62 experimental configurations will be numerically reproduced using a validated 2D shallow-water model. The numerical results, combined with statistical analysis using the JMP software, will help identify the key parameters influencing force variations. The findings provide valuable insights into the role of obstacle characteristics in mitigating or amplifying hydrodynamic loads, with potential applications in flood-resilient urban planning and infrastructure design. This study contributes to the broader objective of improving flood risk assessment by offering a refined understanding of flow-structure interactions in transient flood events. The findings will support the development of guidelines for the strategic placement of barriers and structures in flood-prone areas to optimize protection while minimizing adverse effects.
Ryckmans et al. (Wed,) studied this question.