References of "gerard, Pierre"
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See detailGas injection test in the Callovo-Oxfordian claystone: data analysis and numerical modelling
De la Vaissière, Rémi; Gerard, Pierre; Radu, Jean-Pol ULg et al

in Geological Society, London, Special Publications Online First (2014)

This paper describes a field-scale experiment on gas transport mechanisms performed at Andra’s Underground Research Laboratory (URL) in a clay rock. The experimental layout consists of two parallel ... [more ▼]

This paper describes a field-scale experiment on gas transport mechanisms performed at Andra’s Underground Research Laboratory (URL) in a clay rock. The experimental layout consists of two parallel boreholes that are equipped with multiple packer completions isolating three intervals each, which have been continuously monitoring the pore pressure evolution of the clay rock. Nitrogen gas was injected in the middle test interval of one of the boreholes at increasing rates. The entire gas test comprised six periods of controlled gas injections, each fol-lowed by a shut-in pressure recovery phase. The experimental data are presented along with their interpretation by means of numerical modelling of two-phase flow of gas and water using different numerical codes and different geometrical approaches that include axisymmetric, half-space and full 3D models. An iterative modelling process was used to show step-by-step how an accu-rate description of each component of the experiment system produced a satisfactory reproduc-tion of the experimental data and an improved understanding of the relevant phenomena. For instance, the initial volume of remaining water in the test interval, and the presence of a damaged zone around the boreholes, was important for the models to obtain good agreement with the field data. [less ▲]

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See detailModelling of localised gas preferential pathways in claystone
Gerard, Pierre; Harrington, Jon; Charlier, Robert ULg et al

in International Journal of Rock Mechanics & Mining Sciences (2014), 67

A long-term injection gas test on initially saturated claystone samples under isotropic confining pressure is modelled in a 2D hydro-mechanical framework, which includes the hydraulic anisotropy ... [more ▼]

A long-term injection gas test on initially saturated claystone samples under isotropic confining pressure is modelled in a 2D hydro-mechanical framework, which includes the hydraulic anisotropy. Evidences of localised pathways through the sample have been observed experimentally, which are difficult to reconcile with standard two-phaseflow models. The presence of an embedded pre-existing fracture is included in a continuum finite element model. A hydro-mechanical coupling between the fracture aperture, permeability and the retention properties along the fracture is included in the model. Due to the increase in permeability and the decrease of the air entry pressure induced by the rise in fluid pressure at constant mean total stress, the model provides good agreement with the experimental observations. The discussion offers additional insight into thefluidflow mechanisms into the sample and the processes involved in the development of localised gas pathways. This study allows conclusions to be drawn regarding the performance of the model and its practical limitations. [less ▲]

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See detailAn unsaturated hydro-mechanical modelling of two in-situ experiments in Callovo-Oxfordian argillite
Charlier, Robert ULg; Collin, Frédéric ULg; Pardoen, Benoît ULg et al

in Engineering Geology (2013), 165

The unsaturated behaviour of Callovo-Oxfordian argillite is investigated through the modelling of 2 in-situ experiments. The first test studies the influence of ventilation in a gallery on the hydro ... [more ▼]

The unsaturated behaviour of Callovo-Oxfordian argillite is investigated through the modelling of 2 in-situ experiments. The first test studies the influence of ventilation in a gallery on the hydro-mechanical behaviour of the rock mass. The second test consists in a gas injection in the rock mass from an experimental borehole. A hydro-mechanical model is described and used in the modelling of the experiments. A review of the main hydro-mechanical parameters of argillite is presented. The numerical results highlight the need of a flow boundary condition reproducing the fluid transfers between the surroundings and the rock mass. The influence of dissolved gas on the compressibility of the liquid phase is also emphasised. [less ▲]

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See detailModelling of gas migration in clay formations
Gerard, Pierre; Charlier, Robert ULg; Radu, Jean-Pol ULg et al

Conference (2013)

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See detailCharacterization of gas transport in low-permeability media: two-phase flow analysis of an in-situ experiment
Gerard, Pierre; Radu, Jean-Pol ULg; de la Vaissière, Rémi et al

in POROMECHANICS V: Proceedings of the Fifth Biot Conference on Poromechanics (2013)

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See detailModelling of localised gas pathways in long-term gas injection test
Gerard, Pierre; Collin, Frédéric ULg; Harrington, Jon et al

Poster (2013)

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See detailThe reconstruction of an Atlantic salmon population in the Belgian River Meuse basin. First success and new threats.
Philippart, Jean-Claude ULg; Ovidio, Michaël ULg; Frank, Vincent et al

Conference (2005, April)

A 'Meuse Salmon' project aiming at restoring an Atlantic salmon run in the River Meuse basin was put forward in 1983 (after the discovery of several 'sea trout' in the Meuse near Liège) and started ... [more ▼]

A 'Meuse Salmon' project aiming at restoring an Atlantic salmon run in the River Meuse basin was put forward in 1983 (after the discovery of several 'sea trout' in the Meuse near Liège) and started officially in 1987 as a contribution of Wallonia to the European Year of Environment. In the course of this programme, most dams (3-8 m in height) obstructing the canalised River Meuse in Belgium and The Netherlands have been fitted with modern fish-ways in order to restore the free circulation of diadromous fish species. A second facet of the Salmon Meuse programme consisted in restocking salmonid streams in the Belgian Ardennes with hatchery reared salmon parr and smolt (maximum 200.000 fish per year) from foreign origins (Scotland, Ireland and France). Returning adult salmon have been scientifically recorded in the Meuse in The Netherlands (estuary and lower course) since 1994 but only since the year 2002 in Belgium: 13 (61-79 cm FL) fish in 2002 and 2 (71-76 cm FL) fish in 2003 caught mostly (13 fish) in a new big fish-pass at the Visé-Lixhe dam and (2 fish) in the River Berwinne, a small tributary of the Meuse known as the last spawning place for S. salar in Belgium in the 1920's. Female and male returning salmon in 2002 were successfully artificially reproduced in order to build a captive freshwater brood stock to be used for production of parrs and smolts of the new Meuse strain next autumn. The communication briefly reports on the progress of the program as concerns the salmon culture for stocking in Wallonia, the population dynamics of stocked parrs in nursery rivers, the patterns of upstream and downstream migration of salmon in the Belgian Meuse and its tributaries and the new challenges to meet (impact on salmon of rising water temperature, development of power generation, increasing predation on smolts by piscivorous birds). [less ▲]

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See detailDéfinition des conditions de référence biologiques des rivières en Wallonie
Fauville, Claude; Darchambeau, François ULg; Gosselain, Véronique et al

Report (2004)

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See detailEffects of a micro hydroelectric power plant upon population abundance, mobility and reproduction behaviour of European grayling T. thymallus and brown trout S. trutta in a salmonid river
Ovidio, Michaël ULg; Paquer, Frédéric ULg; Capra, Hervé et al

in Garcia de Jalon, Diego; Vizcaino Martinez, Pilar (Eds.) International Symposium on Ecohydraulics. Aquatic habitat: Analysis & Restoration (2004)

This study examines the potential effects of a new micro hydroelectric power plant (MHPP) on the behaviour (habitat use, movements) and population abundance of European grayling (T. thymallus) and brown ... [more ▼]

This study examines the potential effects of a new micro hydroelectric power plant (MHPP) on the behaviour (habitat use, movements) and population abundance of European grayling (T. thymallus) and brown trout (S. trutta) in the Lhomme (Belgian Ardennes). Thirteen grayling and five brown trout were captured before their spawning period and were manually radio-tracked up to 6 times a week. Population density and biomass were estimated into two different sampling sectors with electric fishing, before and after the MHPP started up. The mobility patterns of grayling and trout in the reach of the river Lhomme influenced by the MHPP strongly contrasted with results obtained in an undisturbed river of the same type in the Belgian Ardennes. Movements were mostly restricted and rarely increased during the spawning period. Spawning took place, but was disturbed by hydropeakings. The population biomass of grayling and trout decreased by 61 % and 23 % respectively, five months after the start-up of the MHPP exploitation. [less ▲]

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