Author(s): Enea Toschini; Christian Tognacca; Mattia Benagli; Riccardo Radogna

Linked Author(s):

Keywords: Morning Glory Spillway; Large Wood Retention; Solid Transport; Physical Modeling; Dam Safety

Abstract: In instances of significant flood events within the Malvaglia Valley catchment, runoff must be effectively managed through the coordinated operation of various dam safety elements. Ensuring controlled discharge of these outflows necessitates the uninterrupted functionality of the Morning Glory Spillway (MGS), particularly safeguarding against obstruction by driftwood. Therefore, it is imperative to devise robust strategies for controlled and reliable discharge, even in the event of substantial large wood input from the catchment area. To address the potential occlusion of the MGS, a series of experiments were conducted on a 1:35 scale physical model in our laboratory in Biasca. The primary objective of these physical model tests was to develop and refine retention structures capable of effectively managing large floating wood and solid debris during flood events. Various protective structure designs and geometries were assessed and optimised through experimentation. Analyses conducted on the physical model facilitated the development of optimised measures for effective floating wood retention and enabled evaluation of the hydrodynamic performance of the entire flood management system under extreme loading conditions. Due to its high retention capacity, ability to maintain stable flow conditions for each discharge, and lower construction costs attributable to reduced weight, the construction of a wide-meshed grid is recommended for protecting the MGS.

DOI: https://doi.org/10.3929/ethz-b-000675921

Year: 2024