Author(s): Vecsernyes Zsolt; Venturi André; Wohl Wend Florent; Gobat Karine; Andreini Nicolas; Jaeger Amandine
Linked Author(s):
Keywords: Physical hydraulic model; Metal-wood breakwater; Wave breaking; Lake shore revitalisation; Ecosystem protection
Abstract: An innovative wave-braking structure was developed at the Laboratory for Applied Hydraulics (LHA) in Geneva-CH. Forming a part of the Lake Geneva shoreline revitalisation programme, the implementation of this structure will protect a future reed bed of Cologny. Raising an embankment-dike in the waters off the coast is not permitted, due to terms of the Suisse Federal Act on the Protection of Waters (RS 814.20) prohibiting the introduction of solid substances into lakes even if they would not lead to pollution. For this reason, CERA civil engineers designed a metal-wood breakwater structure which geometry had to be optimised to achieve high wave-energy dissipation performances. Hence, the Service du lac, de la renaturation des cours d'eau et de la pêche of Geneva mandated the LHA to carry out hydrodynamic and mechanical-structural analyses in an experimental wave tank (Jaeger 2017) and to develop a layout effectively preventing the future reed bed against wind-wave induced harms and erosion of its soil. The alternative analyses carried out at the LHA for 100-year return period wind conditions yielded an innovative breakwater geometry and the set of its optimal distance from the coast, guaranteeing an efficient wave-energy dissipation for the characteristic marling range of Lake Geneva. The mechanical stress and strain data measured on the model served CERA engineers in structural dimensioning. Since the physical hydraulic model analyses yielded robust results the innovative breakwater structure can be implemented along the Cologny coast of Lake Geneva.
Year: 2020