Spillway blockage caused by large wood in reservoirs

Furlan, Paloma (Laboratory of Hydraulic Constructions (LCH) - École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland ; CERIS, Instituto Superior Técnico – Universidade de Lisboa, Lisboa, Portugal) ; Pfister, Michael (School of Engineering and Architecture (HEIA-FR), HES-SO // University of Applied Sciences Western Switzerland) ; Matos, Jorge (CERIS, Instituto Superior Técnico – Universidade de Lisboa, Lisboa, Portugal) ; Schleiss, Anton (Laboratory of Hydraulic Constructions (LCH) - École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland)

Large wood (LW) elements are often transported by rivers into reservoirs during heavy rainfall events. Large wood has important environmental attributes that benefit the diversification of riverine ecosystems. There are several studies dealing with the transport and behaviour of LW inside streams. However, during flood events, LW tends to create jams or blockages at diverse hydraulic structures inside streams, creating significant problems such as discharge limitations and increased water levels. Even though knowledge on the effect of LW at bridges in rivers with relatively high flow velocities starts to be available, the latter is hardly applicable for reservoir approach flow conditions. Understanding LW blockage processes at a reservoir spillway is essential regarding the safety evaluation of a dam and the surrounding areas. The geomorphologic benefits of wood for stream restoration depends also on our present ability to manage jams and the risk they imply for civil structures when blocked. Therefore, series of systematic laboratory experiments were conducted to analyse blockage of floating stems at an ogee crested spillway equipped with piers. Different LW characteristics were represented in a physical model with cylindrical stems. Results associate the size of stem groups to blockage probabilities and the effect blockages can have on the discharge capacity of a spillway.


Keywords:
Conference Type:
full paper
Faculty:
Ingénierie et Architecture
School:
HEIA-FR
Institute:
iTEC - Institut des technologies de l'environnement construit
Subject(s):
Ingénierie
Publisher:
Lyon-Villeurbanne, France, 5-8 September 2018
Date:
2018-09
Lyon-Villeurbanne, France
5-8 September 2018
Pagination:
7 p.
Published in:
Proceedings of the E3S Web of Conferences 40, 02037 (2018), River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, Lyon-Villeurbanne, France, 5-8 September 2018
Numeration (vol. no.):
2018, 40, 02037
DOI:
ISSN:
2267-1242
Appears in Collection:

Note: The status of this file is: restricted


 Record created 2018-10-02, last modified 2018-12-20

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