Author(s): Lisa Besser; Mario Oertel

Linked Author(s): Mario Oertel

Keywords: Non-linear weir; Piano key weir; Labyrinth weir; Numerical simulation; Floodplain

Abstract: With increasing extreme weather events due to climate change the statistical maximum flood discharges in rivers can vary significantly from the initial design flood events. Hence, loads on hydraulic structures such as weirs can reach dangerous levels and the risk of flood plains increases. Non-linear weirs such as Labyrinth Weirs and Piano Key Weirs are effective structures to majorly increase the discharge capacity. With its folded design, non-linear weirs were developed to increase the centerline crest length compared to regular linear weirs and to generate a maximum effective discharge. Non-linear weirs show a lower upstream flow depth compared to linear weirs. However, unlike movable weirs, Labyrinth Weirs and Piano Key Weirs do not have controllable weir gates and therefore no flow rate or head control is possible, resulting in self-induced upstream flow depths. To investigate the upstream influence of non-linear weirs on the spread of floodplains compared to linear weirs, the present paper analyzes upstream flow effects of different types of weirs as well as influences of non-linear weir installation. Numerical simulations are performed for varying geometries for an exemplary river system and resulting head-relationships are presented.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0126-cd

Year: 2023