Publications de Michael Pfister

Effect of blocked driftwood on the hydraulic performance of a gated standard weir

Giovanni De Cesare, Michael Pfister, Loïc Bénet

Driftwood belongs to riverine ecosystems and is stored and transported in every natural stream. Hydraulic structures built in streams typically alter the flow characteristics and might consequently get in conflict with driftwood. The latter can get trapped ...

International Association for Hydro-Environment Engineering and Research (IAHR)2022

Performance and Design of a Stepped Spillway Aerator

Anton Schleiss, Michael Pfister, Stéphane Christian Olivier Terrier

Stepped spillways are frequently limited to specific discharges under around 30 m2/s due to concerns about potential cavitation damages. A small air concentration can prevent such damages and the design of bottom aerators is well established for smooth chu ...

2022

Bottom-Pressure Development Due to an Abrupt Slope Reduction at Stepped Spillways

Anton Schleiss, Michael Pfister, José Pedro Gamito de Saldanha Calado Matos, Mohammad Javad Ostad Mirza

Fluctuating bottom-pressures on stepped chutes are relevant for the spillway design. An abrupt slope reduction causes a local alteration of the bottom-pressure development. Little information is available regarding the air–water flow properties near an abr ...

2022

Force imposée sur un râtelier en amont d’un évacuateur de crue par des bois flottants, et concept pour favoriser le passage des bois flottants

Giovanni De Cesare, Michael Pfister, Loïc Bénet

L’obstruction de l’évacuateur de crue d’un barrage par des bois flottants peut réduire sa capacité hydraulique. Pour limiter cet effet, un râtelier peut être installé pour retenir les bois en amont de la section critique d’écoulement. Sur la base d’une mod ...

2022

Blockage Probability Modeling of Large Wood at Reservoir Spillways With Piers

Anton Schleiss, Michael Pfister, Paloma Furlan, José Pedro Gamito de Saldanha Calado Matos

Large wood increases the morphological and hydraulic complexity of rivers, yet it may block and modify the flood discharge capacity of hydraulic structures. To assess the related risk, blockage probability estimation for hydraulic structures such as reserv ...

2021

Reservoir Level Rise under Extreme Driftwood Blockage at Ogee Crest

Giovanni De Cesare, Michael Pfister, Loïc Bénet

Dams are civil structures essential to modern civilization. However, they can be a threat if not properly designed and operated. A particular risk that potentially can lead to dam failure is the blocking of the spillway inlet with driftwood or debris. This ...

2021

Closure to "Reservoir Level Rise under Extreme Driftwood Blockage at Ogee Crest" by Loic Benet, Giovanni De Cesare, and Michael Pfister

Giovanni De Cesare, Michael Pfister

2021

Statistical accuracy for estimations of large wood blockage in a reservoir environment

Anton Schleiss, Michael Pfister, Paloma Furlan, José Pedro Gamito de Saldanha Calado Matos

The blockage of weirs or bridges by in-stream wood can reduce the flood discharge capacity, leading to hazardous situations. To assess the related risk, blocking probabilities quantifications are needed. However, large wood has a random behaviour and it is ...

SPRINGER2020

Hydraulic design of classical stilling basins downstream of stepped chutes

Anton Schleiss, Giovanni De Cesare, Michael Pfister, José Pedro Gamito de Saldanha Calado Matos, Ivan Stojnic

New design information regarding the hydraulic behaviour of classical stilling basins downstream of stepped chutes is presented and discussed. An extensive experimental campaign revealed that classical stilling basins preceded by stepped chutes cannot be a ...

2020

Bottom pressure characteristics in a stilling basin downstream of a stepped spillway for two different chute slopes

Anton Schleiss, Michael Pfister, Ivan Stojnic, José Pedro Gamito de Saldanha Calado Matos

In the last decades numerous stepped spillways were built, mostly on the downstream face of roller compacted concrete (RCC) dams. Stilling basins are often used as an energy dissipater. Although the hydraulics of stepped chutes was extensively investigated ...

The University of Queensland2020