References of "Collin, Frédéric"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailCyclic and Fatigue Behaviour of Rock Materials: Review, Interpretation and Research Perspectives
Cerfontaine, Benjamin ULiege; Collin, Frédéric ULiege

in Rock Mechanics & Rock Engineering (in press)

The purpose of this paper is to provide a comprehensive state of the art of fatigue and cyclic loading of natural rock materials. Papers published in the literature are classified and listed in order to ... [more ▼]

The purpose of this paper is to provide a comprehensive state of the art of fatigue and cyclic loading of natural rock materials. Papers published in the literature are classified and listed in order to ease bibliographical review, to gather data (sometimes contradictory) on classical experimental results and to analyse the main interpretation concepts. Their advantages and limitations are discussed, and perspectives for further work are highlighted. The first section summarises and defines the different experimental set-ups (type of loading, type of experiment) already applied to cyclic/fatigue investigation of rock materials. The papers are then listed based on these different definitions. Typical results are highlighted in next section. Fatigue/cyclic loading mainly results in accumulation of plastic deformation and/or damage cycle after cycle. A sample cyclically loaded at constant amplitude finally leads to failure even if the peak load is lower than its monotonic strength. This subcritical crack is due to a diffuse microfracturing and decohesion of the rock structure. The third section reviews and comments the concepts used to interpret the results. The fatigue limit and S–N curves are the most common concepts used to describe fatigue experiments. Results published from all papers are gathered into a single figure to highlight the tendency. Predicting the monotonic peak strength of a sample is found to be critical in order to compute accurate S–N curves. Finally, open questions are listed to provide a state of the art of grey areas in the understanding of fatigue mechanisms and challenges for the future. [less ▲]

Detailed reference viewed: 21 (1 ULiège)
Full Text
Peer Reviewed
See detailA fully coupled hydro-mechanical model for the modeling of coalbed methane recovery
Bertrand, François ULiege; Cerfontaine, Benjamin ULiege; Collin, Frédéric ULiege

in Natural Gas science and Engineering (2018)

Most coal seams hold important quantities of methane which is recognized as a valuable energy resource. Coal reservoir is considered not conventional because methane is held adsorbed on the coal surface ... [more ▼]

Most coal seams hold important quantities of methane which is recognized as a valuable energy resource. Coal reservoir is considered not conventional because methane is held adsorbed on the coal surface. Coal is naturally fractured, it is a dual-porosity system made of matrix blocks and cleats (i.e fractures). In general, cleats are initially water saturated with the hydrostatic pressure maintaining the gas adsorbed in the coal matrix. Production of coalbed methane (CBM) first requires the mobilization of water in the cleats to reduce the reservoir pressure. Changes of coal properties during methane production are a critical issue in coalbed methane recovery. Indeed, any change of the cleat network will likely translate into modifications of the reservoir permeability. This work consists in the formulation of a consistent hydro-mechanical model for the CBM production modeling. Due to the particular structure of coal, the model is based on a dual-continuum approach to enrich the macroscale with microscale considerations. Shape factors are employed to take into account the geometry of the matrix blocks in the mass exchange between matrix and fractures. The hydro-mechanical model is fully coupled. For example, it captures the sorption-induced volumetric strain or the dependence of permeability on fracture aperture, which evolves with the stress state. The model is implemented in the finite element code Lagamine and is used for the modeling of one production well. A synthetic reservoir and then a real production case are considered. To date, attention has focused on a series of parametric analyses that can highlight the influence of the production scenario or key parameters related to the reservoir. [less ▲]

Detailed reference viewed: 174 (13 ULiège)
Full Text
Peer Reviewed
See detailComprehensive study of the drying behavior of Boom clay:Experimental investigation and numerical modeling
Hubert, Julien ULiege; Plougonven, Erwan ULiege; Prime, Noémie et al

in International Journal for Numerical and Analytical Methods in Geomechanics (2017)

This paper presents a thermo-hydro-mechanical framework to model the dryingbehavior of Boom clay. First, the experimental campaign conducted Noémie Primeis briefly presented because it is used to validate ... [more ▼]

This paper presents a thermo-hydro-mechanical framework to model the dryingbehavior of Boom clay. First, the experimental campaign conducted Noémie Primeis briefly presented because it is used to validate the model. The data acquisitionand processing is emphasized because of the use of X-ray microtomography to beable to more accurately compare experimental and numerical strain fields. The dif-ferent submodels are introduced. Numerical simulations are performed to illustratethe capability of the proposed model to reproduce the observed behavior. Finally,a comprehensive sensitivity study on several key model parameters associated withthe water retention curve, and the permeability of the medium, is performed to get abetter understanding of the physics behind the coupled model. [less ▲]

Detailed reference viewed: 22 (3 ULiège)
See detailOn the modelling of coupled hydro-mechanical behaviour of interfaces for offshore foundations
Cerfontaine, Benjamin ULiege; Collin, Frédéric ULiege

in Rasmussen, Amalie (Ed.) Marine Engineering: Emerging Developments and Global Challenges (2017)

Detailed reference viewed: 34 (2 ULiège)
Full Text
Peer Reviewed
See detailHydro-mechanical modelling of a coalbed methane production well via a dual-porosity approach
Bertrand, François ULiege; Buzzi, Olivier; Collin, Frédéric ULiege

in Book of Abstracts: 6th International Conference on Coupled THMC Processes in Geosystems (2017, July)

Detailed reference viewed: 110 (0 ULiège)
Full Text
See detailConvective drying : experimental campaign and numerical modelling
Hubert, Julien ULiege; Plougonven, Erwan ULiege; Léonard, Angélique ULiege et al

Conference (2017, June 19)

Detailed reference viewed: 18 (3 ULiège)
Full Text
Peer Reviewed
See detailAnisotropic modelling of Opalinus Clay behaviour: from triaxial tests to gallery excavation application
Bertrand, François ULiege; Collin, Frédéric ULiege

in Journal of Rock-Mechanics and Geotechnical Engineering (2017)

Deep repository in geological formations is the preferential solution considered by many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this ... [more ▼]

Deep repository in geological formations is the preferential solution considered by many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this context, in situ and laboratory tests are conducted on Opalinus Clay to demonstrate the feasibility of deep disposal in this argillaceous formation. This paper presents a constitutive model able to fit the experimental data obtained from some triaxial tests conducted by Jahns [1] on cores from bore hole Schlattingen SLA- 1. The elasto-plastic behaviour of Opalinus Clay is reproduced thanks to a Drucker-Prager model, taking into account the anisotropy behaviour of this sedimentary rock. The objective is to employ a single set of parameters representative of the material. In a second version of the model, the stress-dependency of the elastic properties and damage are taken into account. Finally, the parameters calibrated with experimental tests are used to simulate the excavation of a gallery with a second gradient approach. [less ▲]

Detailed reference viewed: 16 (1 ULiège)
Full Text
Peer Reviewed
See detailValidation of a new elastoplastic constitutive model dedicated to the cyclic behaviour of brittle rock materials
Cerfontaine, Benjamin ULiege; Charlier, Robert ULiege; Collin, Frédéric ULiege et al

in Rock Mechanics & Rock Engineering (2017)

Old mines or caverns may be used as reservoirs for fuel/gas storage or in the context of large-scale energy storage. In the first case, oil or gas is stored on annual basis. In the second case pressure ... [more ▼]

Old mines or caverns may be used as reservoirs for fuel/gas storage or in the context of large-scale energy storage. In the first case, oil or gas is stored on annual basis. In the second case pressure due to water or compressed air varies on a daily basis or even faster. In both cases a cyclic loading on the cavern’s/mine’s walls must be considered for the design. The complexity of rockwork geometries or coupling with water flow requires finite element modelling and then a suitable constitutive law for the rock behaviour modelling. This paper presents and validates the formulation of a new constitutive law able to represent the inherently cyclic behaviour of rocks at low confinement. The main features of the behaviour evidenced by experiments in the literature depict a progressive degradation and strain of the material with the number of cycles. A constitutive law based on a boundary surface concept is developed. It represents the brittle failure of the material as well as its progressive degradation. Kinematic hardening of the yield surface allows the modelling of cycles. Isotropic softening on the cohesion variable leads to the progressive degradation of the rock strength. A limit surface is introduced and has a lower opening than the bounding surface. This surface describes the peak strength of the material andallows the modelling of a brittle behaviour. In addition a fatigue limit is introduced such that no cohesion degradation occurs if the stress state lies inside this surface. The model is validated against three different rock materials and types of experiments. Parameters of the constitutive laws are calibrated against uniaxial tests on Lorano marble, triaxial test on a sandstone and damage-controlled test on Lac du Bonnet granite. The model is shown to reproduce correctly experimental results, especially the evolution of strain with number of cycles. [less ▲]

Detailed reference viewed: 27 (9 ULiège)
Full Text
Peer Reviewed
See detailLoi de comportement pour les argiles naturelles
Ahayan, Sanae ULiege; Cerfontaine, Benjamin ULiege; Collin, Frédéric ULiege

Conference (2017, May 23)

Detailed reference viewed: 24 (8 ULiège)
Full Text
See detailHydro-mechanical modelling of coalbed methane recovery
Bertrand, François ULiege; Buzzi, Olivier; Cerfontaine, Benjamin ULiege et al

Diverse speeche and writing (2017)

Detailed reference viewed: 106 (2 ULiège)
Full Text
Peer Reviewed
See detailModeling the strain localization around an underground gallery with a hydro-mechanical double scale model; effect of anisotropy
van den Eijnden, AP; Bésuelle, Pierre; Collin, Frédéric ULiege et al

in Computers and Geotechnics (2017), 85

Detailed reference viewed: 73 (3 ULiège)
Full Text
See detailEtude du comportement des Monopieux XL dans les sols argileux
Ahayan, Sanae ULiege; Cerfontaine, Benjamin ULiege; Kotronis, Panagiotis et al

Scientific conference (2017, February)

Detailed reference viewed: 26 (8 ULiège)
Full Text
See detailImpact of thermal cycles on the mobilization of shear strength for energy piles
Vasilescu, R.; Kotronis, P.; Dano, C. et al

Conference (2017)

Detailed reference viewed: 14 (0 ULiège)
Full Text
See detailCharacterisation of clays from the Kinshasa region (D.R.Congo) used for manufacture of raw earth products
Mango-Itulamya, Lavie Arsène ULiege; Collin, Frédéric ULiege; Courtejoie, Fabienne ULiege et al

in Galindo, Alberto López (Ed.) Scientific Research Abstracts (2017)

This work aims at valorising these natural clay resources in another sector of construction which is the raw earth, and by this, defining them as a sustainable and energy-saving alternative.

Detailed reference viewed: 32 (11 ULiège)
Full Text
Peer Reviewed
See detailOn the Variable Dilatancy Angle in Rocks Around Underground Galleries
Salehnia, Fatemeh ULiege; Collin, Frédéric ULiege; Charlier, Robert ULiege

in Rock Mechanics & Rock Engineering (2016)

Correct estimation of the dilatant behavior of a rock has an essential role in a realistic numerical simulation of the fracturing threshold during the rock deformation process and its post-failure ... [more ▼]

Correct estimation of the dilatant behavior of a rock has an essential role in a realistic numerical simulation of the fracturing threshold during the rock deformation process and its post-failure response, based on experimental and field observations. This importance has been poorly treated in most of the numerical analyses dealing with the rock engineering common problems such as deep excavations. The dilatancy angle as a commonly used parameter for describing the dilatation response of a rock is mostly simplified to be a constant value. Contrarily, a literature review declares the inadequacy of this approach in those rock mechanics applications. In the present paper, a new formula for considering the variable dilatancy angle is presented which relates this parameter to the plastic shear strain in the course of a loading procedure. It is aimed at characterizing an evolution of the dilatant or contracting volumetric response of a rock as well as giving the possibility to simulate a dilatant/contracting transitional behavior. The model is applied to simulate the development of strain localization, in shear band mode, within the inevitable excavation damaged zone created around an underground opening in rock. It is illustrated that using the model of variable dilatancy angle in a deep excavation modeling could help to better reproduce the fractures development around the opening in the course of tunneling. [less ▲]

Detailed reference viewed: 44 (12 ULiège)