Preliminary assessment of the efficiency of flood walls at various angles of flow deflection

Manousos Valyrakis, Athanasios-Theodosios Alexakis

Monday 29 june 2015

17:51 - 17:54h at North America (level 0)

Themes: (T) Flood risk management and adaptation, (ST) Adaptation measures, Poster pitches

Parallel session: Poster pitch: 2I: FloodRisk - Adaption

This study details the design and utilization of a scaled physical model of a novel prototype (rising) floodwall system, aiming at assessing the capacity of the same model under different implementations (changing the degree of flow deflection). These experiments are carried out at one of the research flumes in the Water Engineering laboratory of the University of Glasgow. These involve an experimental routine where the increase of force applied on the floodwall is measured for different angles of attack (level of deflection of the water from the stream's centerline). At greater degrees of flow deflection, the effect of super-elevation results in a higher water surface elevation, which if accounted for reduces the maximum flow that can be routed, without exceeding the floodwall height. These results can be considered upon the implementation phase of floodwalls: while it may be more economical to have a rapid change to the flow direction, the maximum flow that can be securely routed through will be decreased and forces on the wall increased (requiring better support systems). This is of interest when the floodwalls are placed at any arrangement other than parallel to the flow (e.g. along river bends in meandering channels or at river junctions). Such considerations can lead to site-specific optimal designs of direct flood defenses with the rising floodwall system, both in terms of product performance as well as cost efficiency.