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See detailHydraulic behavior of Piano Key Weirs: experimental approach
Machiels, Olivier ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Janssen, Robert; Chanson, Hubert (Eds.) 3rd Int. Junior Researcher and Engineer Worjshop on Hydraulic Structures (2010, May)

The Piano Key Weir (PKW) is a particular geometry of weir similar to a labyrinth shape that features overhanging cycle ends to reduce the base length. Together with its high discharge capacity for low ... [more ▼]

The Piano Key Weir (PKW) is a particular geometry of weir similar to a labyrinth shape that features overhanging cycle ends to reduce the base length. Together with its high discharge capacity for low heads, this geometric feature makes the PKW an interesting solution for dam rehabilitation, permitting the placement of the weir directly on dam crest. However, PKW stays a new type of weir, firstly designed in 2001 and built for the first time in 2006 by Electricité de France (EDF). Even if the first experimental studies confirmed its discharge capacities, lacks persist in the understanding of the flow behaviour upstream, along and downstream of this complex structure. This paper presents the mean results and observations obtained from experiments on a large scale model of PKW. The hydraulics of the structure is clarified based on measurements of water depths, pressures, velocities and discharges on each part of the weir. These observations explain the effect of geometric improvements proposed in former studies. [less ▲]

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See detailHydraulic behaviour of greened porous pavements: a physical study
Straet, Frederic; Beckers, Eléonore ULg; Degre, Aurore ULg

(2008)

Detailed reference viewed: 49 (16 ULg)
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See detailHydraulic modelling in civil and environmental engineering
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Scientific conference (2013, May 08)

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See detailHydraulic modelling along river Ourthe
Dewals, Benjamin ULg; Detrembleur, Sylvain ULg; Archambeau, Pierre ULg et al

Conference (2007, June 01)

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See detailHydraulic modelling along river Ourthe considering impacts of climate change
Dewals, Benjamin ULg

Conference (2007, June 01)

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See detailHydraulic modelling of Piano Key Weirs: a composite approach
Erpicum, Sébastien ULg; Machiels, Olivier ULg; Archambeau, Pierre ULg et al

in Proceedings of International workshop on Piano Key Weir for In-stream Storage and Dam Safety - PKWISD-2012 (2012, May)

During the last few years, several piano key weirs (PKWs) have been built in France and abroad. Thanks to the reduced footprint and high release capacities of this new type of weir, making it particularly ... [more ▼]

During the last few years, several piano key weirs (PKWs) have been built in France and abroad. Thanks to the reduced footprint and high release capacities of this new type of weir, making it particularly suited for concrete dams rehabilitation, lots of other projects in various countries are under construction or study. The prototype use of PKW requires knowledge about its structural behaviour, hydraulic capacities as well as integration into dams’ environment. This paper aims at presenting numerical and physical modelling works performed at the University of Liege to address the last two items. In particular, large scale physical modelling and parametric scale models have enabled to understand the hydraulic behaviour of the structure and to highlight its most influencing geometric parameters as well as their best variation interval depending on various criteria related to the weir design (discharge efficiency, cost…). A 1D numerical model has also been developed based on these experimental investigations. It enables to predict in a few minutes, with 10% accuracy, the discharge capacity of a given PKW geometry within its usual range of operation head. This model, available as a freeware from http://www.pk-weirs.ulg.ac.be, constitutes a key tool for the first design of such weirs. Finally, the scale model studies of major projects such as Raviège dam (France) for Electricité de France - EDF and Ouldjet Mellegue Project (Algeria) for Coyne et Bellier – Tractebel Engineering enable to confront theoretical predictions with experimental results and to address the problem of PKW integration on dam crests. [less ▲]

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See detailHydraulic modelling of the river Meuse
Dewals, Benjamin ULg

Conference (2013, September)

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See detailHydraulic studies for the Taoussa project, Mali
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Proceedings of Africa 2013 conference (CD-Rom) (2013)

The Taoussa Project is a component of a large development scheme of the Niger River in the north-eastern part of Mali aiming at reducing desertification and improving socio-economic activity. It is mainly ... [more ▼]

The Taoussa Project is a component of a large development scheme of the Niger River in the north-eastern part of Mali aiming at reducing desertification and improving socio-economic activity. It is mainly made of a rockfill dam with central core around 18 m high and 1,000 m long across the valley of the Niger River, 130 km upstream of the town of Gao in the eastern part of Mali. The dam is equipped with a 25 MW hydroelectric power plant, a lock, a dock and a spillway. The spillway is made of a gated ogee crested weir divided into 10 bays and a downstream stilling basin, with a maximum discharge capacity of 3,100 m³/s. 210 km of high tension overhead cables and a 130 km long road complete the Project. The multipurpose Taoussa dam will enable the sustainable development of the Project area by securing water resources, increasing low-water level discharges downstream, creating a link between road and fluvial transports (dock) and producing electricity. The Ministère de l’Energie, des Mines et de l’Eau du Mali - Autorité pour l’Aménagement de Taoussa -commissioned Coyne et Bellier – Tractebel Engineering in 2006 to perform the detailed studies for the Project. In this framework, the hydraulic studies have been performed by the Laboratory of Engineering Hydraulics (HECE) of the University of Liege. These hydraulic studies, depicted in details in the paper, have been carried out successively by two complementary approaches: a first step realized on the basis of numerical modelling to study the flows at the scale of the reservoir and the river, and a second experimental investigation, using a scale model, to analyse in details the spillway operation conditions. They consider varied problems from large scale flow conditions in the reservoir during the spillway operation and hydrodynamic interactions between the dam, the lock and the hydroelectric power plant to validation and optimization of the hydraulic design and dimensions of the gated spillway and the stilling basin or release conditions downstream of the project structures, including the temporary derivation stage. [less ▲]

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See detailHydraulique Appliquée
Pirotton, Michel ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

Learning material (2007)

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See detailHydraulique Urbaine
Pirotton, Michel ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

Learning material (2008)

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See detailHydro and Hydro-Mechanical Modelling of Ventilation Test in Clayey Rocks
Pardoen, Benoît ULg; Talandier, Jean; Charlier, Robert ULg et al

in Mancuso, Claudio; Jommi, Cristina; D'Onza, Francesca (Eds.) Unsaturated Soils: Research and Applications (2012)

Hydro and hydro-mechanical numerical modellings are performed in order to acquire a better understanding of clayey rock behaviour and transfers occurring during an in situ ventilation test. The test is ... [more ▼]

Hydro and hydro-mechanical numerical modellings are performed in order to acquire a better understanding of clayey rock behaviour and transfers occurring during an in situ ventilation test. The test is performed in an experimental gallery that is part of an underground research laboratory. A biphasic flow model for unsaturated soil and an elasto-plastic constitutive law are used for the host formation. The models include exchange condition of fluid mass, anisotropy and the excavation damaged zone around the gallery. Finally, the ventilation test is reproduced and the model is calibrated based on the matching between numerical results and experimental measurements. [less ▲]

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See detailHydro and hydro-mechanical modelling of ventilation test in clayey rocks
Pardoen, Benoît ULg; Charlier, Robert ULg; Collin, Frédéric ULg et al

Poster (2011, October 03)

Long-term repository of radioactive waste in deep argillaceous geological media needs a good understanding of the host formation behaviour. Considering the safety function of the formation and the need of ... [more ▼]

Long-term repository of radioactive waste in deep argillaceous geological media needs a good understanding of the host formation behaviour. Considering the safety function of the formation and the need of low permeability, the behaviour of the excavation damaged zone (EDZ) is a major issue. Because drainage may modify the structure and the size of this zone, a ventilation test (SDZ) is realised by the French national radioactive waste management agency (ANDRA) in an experimental gallery of the Meuse/Haute-Marne underground research laboratory located in Callovo-Oxfordian claystone. The aim is to characterise the effect of the desaturation and possible resaturation of the damaged zone due to controlled ventilation. Numerical modellings are performed to reproduce the ventilation test. A biphasic flow model in unsaturated soil and an elasto-plastic constitutive law are used for the host formation. A nonclassical boundary condition has been developed in order to model the exchanges between the cavity and the rock. Numerical results show that it is possible to calibrate the models to obtain a satisfactory reproduction of the in situ experimental measurements and a better understanding of the fluid transfer around the gallery during the ventilation test. [less ▲]

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See detailHydro-mechanical behavior of fractures: 2D, F.E.M. modeling
Guiducci, Chiara; Pellegrino, Antonio; Radu, Jean-Pol ULg et al

in Auriault, J. L.; Geindreau, C.; Royer, P. (Eds.) Poromechanics II (2002)

A numerical approach for modeling the coupled hydro-mechanical fracture behavior is proposed. The movement of fluids through rock fractures and consequently the evolution of their hydraulic conductivity ... [more ▼]

A numerical approach for modeling the coupled hydro-mechanical fracture behavior is proposed. The movement of fluids through rock fractures and consequently the evolution of their hydraulic conductivity is an important subject in many petroleum related activities, mainly concerning the change of well productivity during the reservoir life. It is well known that the flow in the fractures is strongly controlled by the fracture apertures. Recent investigations on the distribution of the apertures in natural fractures suggest that the cubic law can, better than the Darcy law, predict the fluid flux through rough walled fractures as long as the appropriate average fracture aperture is used. A finite element code is developed to predict the influence that the stresses variation in the fracture has on the distributed hydraulic conductivity field. The proposed model combines the stochastic cubic law with a non-linear deformation function (hyperbolic) that is suggested to describe the stress-closure/opening curves of the joints and that allows to couple together the hydraulic and the mechanic fracture behavior. The relationships used and the validity of the present model are tested by means of the comparison between experimental data and numerical predictions (Bart 2000) in various bound-ary and loading conditions. Comparisons between the proposed new model and a no coupled one have also been performed. They show that the proposed coupled model allows for a more realistic description of the fracture behavior. [less ▲]

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See detailHydro-mechanical modeling of damage due to underground excavation in hardened clay
Levasseur, Séverine ULg; Collin, Frédéric ULg; Frieg, Bernd et al

in Pietruszczak, Stan; Pande, Gyan; Tamagnini, Claudio (Eds.) et al Computational Geomechanics (2009)

A zone with significant irreversible processes and significant changes in flow and transport properties is expected to be formed after underground excavations. The perturbation of the excavation could ... [more ▼]

A zone with significant irreversible processes and significant changes in flow and transport properties is expected to be formed after underground excavations. The perturbation of the excavation could lead to a significant increase of the permeability, related to diffuse and/or localized crack proliferation in the material. The main objective of the study is to model these processes at large scale in order to assess their impacts on the performance of radioactive waste geological repositories. This paper concerns more particularly the hydro-mechanical modeling of a long term dilatometer experiment performed in Mont Terri Rock Laboratory in Switzerland. The proposed model defines the permeability as a function of the aperture of the cracks that are generated during the excavation. With this model, the permeability tensor becomes anisotropic. These developments are validated with the results of the experiment. [less ▲]

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See detailHydro-mechanical modelling of the development of preferential gas pathways in claystone
Gerard, Pierre ULg; Harrington, Jon; Charlier, Robert ULg et al

in Mancuso, Claudio; Jommmi, Cristina; D'Onza, Francesca (Eds.) Unsaturated Soils: Research and Applications (volume 2) (2012)

During long-term repository of radioactive waste in argillaceous formation, the gas migration in the host formation and in the engineered barriers is a crucial issue, because it could affect the safety ... [more ▼]

During long-term repository of radioactive waste in argillaceous formation, the gas migration in the host formation and in the engineered barriers is a crucial issue, because it could affect the safety function of the clay barriers. Gas migration tests on Callovo-Oxfordian argillite have been performed by the British Geological Survey. The observations show that gas migration is often accompa-nied by the development of preferential pathways, which propagate through the sample. Hydro-mechanical numerical modelling of these tests is performed. It ap-pears that a continuum approach to the movement of gas is not sufficient to repro-duce the experimental observations. A coupling between deformation of the me-dium, permeability and air entry pressure is proposed. The numerical results show that such coupling play an important role in a successful simulation of such gas flows. [less ▲]

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See detailHydro-mechanical modelling of the Excavation Damaged Zone around an underground excavation at Mont Terri Rock Laboratory
Levasseur, Séverine ULg; Charlier, Robert ULg; Frieg, Bernd et al

in International Journal of Rock Mechanics & Mining Sciences (2010), 47(3), 414-425

A zone with significant irreversible deformations and significant changes in flow and transport properties is expected to be formed in indurated clay around underground excavations. The stress ... [more ▼]

A zone with significant irreversible deformations and significant changes in flow and transport properties is expected to be formed in indurated clay around underground excavations. The stress perturbation around the excavation could lead to a significant increase of the permeability, related to diffuse and/or localized crack propagation in the material. The main objective of the study is to model these processes at large scale in order to assess their impacts on the performance of radioactive waste geological repositories. This paper concerns more particularly the hydro-mechanical modelling of a long term dilatometer experiment performed in Mont Terri Rock Laboratory in Switzerland within the Selfrac Project. The proposed model defines the permeability as a function of the aperture of the cracks that are generated during the excavation. With this model, the permeability tensor becomes anisotropic. Advantages and drawbacks of this approach are described thanks to the results of the Selfrac long term dilatometer experiment. [less ▲]

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See detailHydro-mechanical numerical modelling of geotechnical problems using local second gradient models
Chambon, René; Collin, Frédéric ULg

in Vermeer, Peter; Ehlers, W.; Herrmann, H. J. (Eds.) Modelling of cohesive-Frictional Materials (2004)

The paper presents some applications of a local second gradient theory used to describe the mechanical behavior of a continua. This theory has been developed in order to avoid some well known drawbacks of ... [more ▼]

The paper presents some applications of a local second gradient theory used to describe the mechanical behavior of a continua. This theory has been developed in order to avoid some well known drawbacks of classical theories, when softening and/or localization occur in a computation. This theory is extended and then applied in a hydromechanical coupled problem, in the case of fully saturated geomaterials. The corresponding finite element method taking into account the geometrical non linearities is detailed. Preliminary results using the finite element code developed in this context are then discussed and allow to study post localization behavior. [less ▲]

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See detailHydrocarbons contamination of smoked shrimp, an expanding food condiment in Beninese local markets
Kpoclou, Euloge; Brose, François ULg; Anihouvi, V.B. et al

Poster (2013, April 18)

Detailed reference viewed: 14 (6 ULg)