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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 ▲]

Detailed reference viewed: 132 (5 ULg)
See detailHYDRO-MECHANICAL COUPLING IN A FE 2 METHOD
van den Eijnden, Abraham Pieter ULg; Plua, Carlos; Bésuelle, Pierre et al

Scientific conference (2014, October 01)

Detailed reference viewed: 7 (1 ULg)
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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 ▲]

Detailed reference viewed: 117 (20 ULg)
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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 ▲]

Detailed reference viewed: 47 (1 ULg)
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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 ▲]

Detailed reference viewed: 146 (17 ULg)
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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 ▲]

Detailed reference viewed: 65 (2 ULg)
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See detailHydro-mechanical simulation in a deep excavation in Boom Clay
Hong, P.Y.; Cui, Y.J.; Pereira, J.M. et al

Poster (2015, March)

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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)

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See detailA hydrochemical - isotopic approach for assessing factors controlling the regional pollution of an urban aquifer
Gesels, Julie ULg; Orban, Philippe ULg; Popescu, Ileana-Cristina et al

Poster (2015, June 24)

The alluvial aquifer of the Meuse River is contaminated at regional scale in the urbanized and industrialized area of Liège in Belgium, in particular inorganics pollutants such as sulfate, nitrate and ... [more ▼]

The alluvial aquifer of the Meuse River is contaminated at regional scale in the urbanized and industrialized area of Liège in Belgium, in particular inorganics pollutants such as sulfate, nitrate and ammonium. The sources of those contaminants are numerous: brownfields, urban waste water, subsurface acid mine drainage from former coal mines, atmospheric deposits related to former pollutants emissions in the atmosphere ... Sulfate, nitrate and ammonium are both typical pollutants of the aquifer and tracers of the possible pollution sources. In the Water Framework Directive context, a detailed hydrogeochemical characterization of groundwater was performed. The aim is to determine the origin of the inorganic contaminations, the main processes contributing to poor groundwater quality and the spatial extent of the contaminations. A large hydrochemical sampling campaign was performed, based on 71 selected representative sampling locations, to better characterize the different vectors (end-members) of contamination of the alluvial aquifer and their respective contribution to groundwater contamination in the area. Groundwater samples were collected and analyzed for major and minor compounds and metallic trace elements. The analyses also include stable isotopes in water, sulfate, nitrate, ammonium, dissolved inorganic carbon, boron and strontium. Different hydrogeochemical approaches are combined to obtain a global understanding of the hydrogeochemical processes at regional scale. Hydrochemical interpretations are based on classical diagrams, spatial distribution maps, geochemical equations, multivariate statistics such as self-organizing maps and isotopic analyses. With this combined approach, the location of the contaminant sources and most contaminated sectors of the alluvial aquifer together with a better understanding of geochemical processes involved are obtained. Redox processes strongly influence the composition of groundwater, specifically for compounds degrading the quality of groundwater in the area (sulfate, nitrate and ammonium). The highest concentrations of sulfate can be associated with the post-mining stage in the acid mine drainage process. Various reactions involving nitrogen compounds have been identified and allow a better understanding of causes of high concentrations of ammonium and nitrate. Denitrification and sulphate reduction are also demonstrated based on isotopic ratios. [less ▲]

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See detailHydroCube: a new entity-relationship hydrogeological data model
Wojda, Piotr; Brouyère, Serge ULg; Derouane, Johan et al

in Hydrogeology Journal (2010), 18(8), 1953-1962

Managing, handling, and accessing hydrogeological information depend mainly on the applied hydrogeological data models, which differ between institutions and across countries. Growing interest in ... [more ▼]

Managing, handling, and accessing hydrogeological information depend mainly on the applied hydrogeological data models, which differ between institutions and across countries. Growing interest in hydrogeological information diffusion, combined with a need for information availability, require the convergence of hydrogeological data models to make hydrogeological information accessible to multiple users such as universities, administrations, water suppliers, and research organisations. Furthermore, because hydrogeological studies are complex, they require a large variety of high-quality hydrogeological data with appropriate metadata in clearly designed and coherent structures. A need therefore exist to develop and implement hydrogeological data models that cover, as much as possible, the full hydrogeological domain. To respond to these requirements, a new data model, called HydroCube, has been developed for the Walloon Region in Belgium. The HydroCube model presents an innovative holistic “project-based” approach, which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. This approach enables to store data about the project localisation, hydrogeological equipment, related observations and measurements. In particular, the model focuses on specialized hydrogeological field experiments, such as pumping and tracer tests. This logical data model uses entity-relationship diagrams and it has been implemented in the MS Access environment as the HydroCube database. It has been additionally enriched with a fully functional user-interface. [less ▲]

Detailed reference viewed: 108 (25 ULg)
See detailHydrodéchloration catalytique de composés organochlorés
Heinrichs, Benoît ULg

Learning material (2004)

Detailed reference viewed: 16 (2 ULg)
Peer Reviewed
See detailHydrodéchloration sélective du 1,2-dichloroéthane en éthylène sur un catalyseur xérogel Pd-Ag/SiO2
Heinrichs, Benoît ULg; Delhez, P.; Pirard, Jean-Paul ULg et al

in Récents Progrès en Génie des procédés (1997, September 24)

Detailed reference viewed: 19 (7 ULg)
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See detailHydrodechlorination of 1,2-dichloroethane into ethylene : selectivity of Pd-Ag alloys of known surface composition
Heinrichs, Benoît ULg; Lambert, Stéphanie ULg; Schoebrechts, Jean-Paul et al

in Heterogeneous Catalysis, Proceedings of the 9th International Symposium (2000, September 23)

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See detailHydrodechlorination of 1,2-dichloroethane on Pd-Ag catalysts supported on tailored texture carbon xerogels
Job, Nathalie ULg; Heinrichs, Benoît ULg; Ferauche, Fabrice et al

in Catalysis Today (2005), 102

Porous carbon xerogels synthesized in a previous study were investigated as catalysts supports. The support chosen was a micro-mesoporous carbon xerogel obtained from the pyrolysis of a resorcinol ... [more ▼]

Porous carbon xerogels synthesized in a previous study were investigated as catalysts supports. The support chosen was a micro-mesoporous carbon xerogel obtained from the pyrolysis of a resorcinol-formaldehyde resin whose synthesis variables were fixed at suitable values. Palladium and silver were deposited on this tailored texture carbon by co-impregnation using a solution of palladium and silver nitrates in nitric acid and water. Several catalysts were prepared with various Pd and Ag global contents, the latters being measured experimentally. Alloy particles, detected in all bimetallic samples, were studied by a combination of various techniques that enabled us to obtain their size as well as their bulk and surface composition. When present, the fraction of unalloyed silver was also calculated. The characterization data were related to the results of catalytic tests obtained for selective hydrodechlorination of 1,2-dichloroethane into ethylene. Results show that when the Ag content is too high, pure Ag particles are formed and the alloy composition remains constant. As a consequence, the surface composition of the alloy is constant as well and the catalytic tests lead to similar results. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailHydrodechlorination of 1,2-dichloroethane on Pd-Ag catalysts supported on texture-tailored materials
Job, Nathalie ULg; Heinrichs, Benoît ULg; Ferauche, Fabrice et al

Conference (2004, July 19)

Detailed reference viewed: 10 (0 ULg)