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CRC Press eBooks, Dec 18, 2013

HAL (Le Centre pour la Communication Scientifique Directe), May 28, 2013

CRC Press eBooks, Jun 17, 2010

-Le Laboratoire Central des Ponts et Chaussés a acquis un simulateur de séisme pour compléter son... more -Le Laboratoire Central des Ponts et Chaussés a acquis un simulateur de séisme pour compléter son équipement d'essais géotechniques, en modèles réduits centrifugés. Cette communication vise à présenter les premières applications de cet outil de modélisation physique qui portent sur l'étude du comportement d'un pieu flottant isolé et d'un groupe de deux pieux travaillant en pointe. ABSTRACT-The Laboratoire Central des Ponts et Chaussées has purchased an earthquake simulator to supplement its equipment for the geotechnical centrifuge. This communication presents the first applications of this physical modelling tool concerning the seismic responses of a floating pile and that of a group of two endbearing piles.

Note: Roches Reference LMR-REPORT-2005-001 Record created on 2006-11-09, modified on 2017-12-10

Applied Clay Science, Jun 1, 2004

The clay minerals are among the first silicated minerals to be transformed physically and chemica... more The clay minerals are among the first silicated minerals to be transformed physically and chemically during changes of temperature, pressure, relative humidity and fluid composition. One of the first physical processes, extremely rapid, is the hydration and/or dehydration of swelling clays minerals. These processes could generate changes of the clay structure and consequently the texture of an argillaceous rock. In order to observe in situ structural modifications on a deep argillaceous rock ''argillite'' (Parisian basin, in France) according hydration-dehydration cycles, an Environmental Scanning Electron Microscope (ESEM) was used. This instrument allows the possibility to observe geological samples in their natural state without preliminary preparation or modification. Two types of samples were prepared, parallel and perpendicular to the lithology. Then, each sample was submitted to three water condensation/evaporation cycles. The observed samples were from the Callovo-Oxfordian formations in HTM 80743, HTM 983, HTM 02618 and EST 2159 cores. ESEM observations show that the water sensitivity of these bulk samples depends directly on the clay mineral proportion in the rock, and on the clay family present. It is also obvious that the water sensitivity depends on the anisotropy of the pore structure and the particle size and total porosity. The main structural modifications observed were the cracking of the surface, particles aggregation/disaggregating and opening/closing of pores and/or cracks.

Soil Dynamics and Earthquake Engineering

Soil Dynamics and Earthquake Engineering

Lateral spreading of a submerged slope and validation of generalized scaling laws for LEAP-ASIA-2019

Geotechnical Earthquake Engineering and Soil Dynamics V, 2018

© 2018 American Society of Civil Engineers. Twenty-four centrifuge model tests have been conducte... more © 2018 American Society of Civil Engineers. Twenty-four centrifuge model tests have been conducted at nine different geotechnical centrifuge facilities around the world as part of the international LEAP effort (liquefaction experiments and analysis projects). All of the centrifuge models represent a 4 m deep 5 degree sloping submerged sand deposit. The mean effective PGA of the input motion for all of the experiments was approximately 0.15 g and the mean relative density was approximately 65%, but the effective PGA's varied between about 0.07 g and 0.3 g, and the relative densities varied between about 40% and 75%. The test matrix was designed to enable experimental quantification of not only the median response but also the trend and sensitivity of the model response to density and shaking intensity. Quantification of the sensitivity of the response to initial conditions is a prerequisite for objective evaluation of the quality of the model test data. In other words, a discrepancy between two experiments should be evaluated after accounting for the uncertainty in the initial conditions and the sensitivity of the response to initial conditions. For the first time, a sufficient number of experiments has been performed on a similar problem to provide meaningful quantitative evaluation of the trend between PGA, density, and displacement. The sensitivity is quantified by the gradient of the trend and the uncertainty of the trend is quantified from the residuals between the fitting data and the trend.

Soil Dynamics and Earthquake Engineering, 2012

Seismic behavior of inclined piles has been considered detrimental for years. However, recent res... more Seismic behavior of inclined piles has been considered detrimental for years. However, recent researches show that battered piles can have a beneficial effect. In this framework, a series of centrifuge tests on an inclined pile group is performed. The analysis is based on the comparative response of two 2 Â 1 simplified pile groups: one with vertical piles and the other with one vertical and one inclined pile. The response of these pile groups to repeated earthquakes or sinusoidal inputs is analyzed through the response frequencies, the envelop curves of bending moment profiles, the axial loads measured in both piles and the kinematic response of the cap. Results highlight that the effect of inclined pile is highly influenced by the frequency content of the input. In addition, the inclined pile induces non-negligible residual bending moments, higher horizontal stiffness at the pile cap and larger rotation.

Proceedings of the Sixth International Conference on Physical Modelling in Geotechnics, 6th ICPMG '06, Hong Kong, 4 - 6 August 2006, 2006

The SELFRAC project aimed to study the fractures within the Excavation Damaged Zone (EDZ) around ... more The SELFRAC project aimed to study the fractures within the Excavation Damaged Zone (EDZ) around galleries in the Boom clay and Opalinus clay formations and their possible sealing/healing with time. Tests carried out at LMR-EPFL aimed at quantifying on the same sample the increase in permeability induced by a localised crack, and subsequently the potential self-sealing process of this localised crack. The tests were performed in triaxial cells on hollow cylindrical samples and consisted in radial permeability measurements before and after the tensile fracturing of the clayey samples. In both clays, sealing processes are observed. However, the reduction in hydraulic conductivity after fracturing is much slower in Opalinus clay than the one in Boom clay (extremely fast recovering of the virgin clay permeability).

Note: Roches Reference LMR-REPORT-2005-001 Record created on 2006-11-09, modified on 2017-12-10

Bulletin of Earthquake Engineering

ABSTRACT Cet article rappelle les lois de similitude applicables en centrifugation, décrit la cen... more ABSTRACT Cet article rappelle les lois de similitude applicables en centrifugation, décrit la centrifugeuse géotechnique et le simulateur de séismes acquis par le LCPC (Laboratoire Central des Ponts et Chaussées) en 2006. Il présente également les nouveaux équipements développés pour réaliser les essais sismiques, en particulier le conteneur laminaire de type 'Equivalent Shear Beam' conçu pour simuler une masse infinie de sol avant liquéfaction.

Sont presentes trois nouveaux equipements de recherche experimentale dans le domaine sismique en ... more Sont presentes trois nouveaux equipements de recherche experimentale dans le domaine sismique en macro-gravite, implantes dans la centrifugeuse du Laboratoire Central des Ponts et Chaussees (LCPC Nantes). Le simulateur de seismes ID permet d'appliquer, soit un sinus a la base du modele, soif un seisme reel a contenu large bande. L'originalite de ce simulateur tient dans le mouvement reciproque de la charge utile et des contrepoids limitant la transmission des vibrations a la centrifugeuse. Les premiers resultats de la simulation d'un seisme sont presentes. Le second equipement est le conteneur laminaire de type ESB (Equivalent Shear Beam). Le troisieme est une centrale d'acquisition haute frequence.

International Journal of Heat and Mass Transfer, 2004

... F. Homand, A. Giraud Corresponding Author Contact Information , E-mail The Corresponding Auth... more ... F. Homand, A. Giraud Corresponding Author Contact Information , E-mail The Corresponding Author , E-mail The Corresponding Author , S. Escoffier 1 , A. Koriche and D. Hoxha. ... First approach explicit or semi-explicit solutions for the direct problems are used. ...

CRC Press eBooks, Dec 18, 2013

HAL (Le Centre pour la Communication Scientifique Directe), May 28, 2013

CRC Press eBooks, Jun 17, 2010

-Le Laboratoire Central des Ponts et Chaussés a acquis un simulateur de séisme pour compléter son... more -Le Laboratoire Central des Ponts et Chaussés a acquis un simulateur de séisme pour compléter son équipement d'essais géotechniques, en modèles réduits centrifugés. Cette communication vise à présenter les premières applications de cet outil de modélisation physique qui portent sur l'étude du comportement d'un pieu flottant isolé et d'un groupe de deux pieux travaillant en pointe. ABSTRACT-The Laboratoire Central des Ponts et Chaussées has purchased an earthquake simulator to supplement its equipment for the geotechnical centrifuge. This communication presents the first applications of this physical modelling tool concerning the seismic responses of a floating pile and that of a group of two endbearing piles.

Note: Roches Reference LMR-REPORT-2005-001 Record created on 2006-11-09, modified on 2017-12-10

Applied Clay Science, Jun 1, 2004

The clay minerals are among the first silicated minerals to be transformed physically and chemica... more The clay minerals are among the first silicated minerals to be transformed physically and chemically during changes of temperature, pressure, relative humidity and fluid composition. One of the first physical processes, extremely rapid, is the hydration and/or dehydration of swelling clays minerals. These processes could generate changes of the clay structure and consequently the texture of an argillaceous rock. In order to observe in situ structural modifications on a deep argillaceous rock ''argillite'' (Parisian basin, in France) according hydration-dehydration cycles, an Environmental Scanning Electron Microscope (ESEM) was used. This instrument allows the possibility to observe geological samples in their natural state without preliminary preparation or modification. Two types of samples were prepared, parallel and perpendicular to the lithology. Then, each sample was submitted to three water condensation/evaporation cycles. The observed samples were from the Callovo-Oxfordian formations in HTM 80743, HTM 983, HTM 02618 and EST 2159 cores. ESEM observations show that the water sensitivity of these bulk samples depends directly on the clay mineral proportion in the rock, and on the clay family present. It is also obvious that the water sensitivity depends on the anisotropy of the pore structure and the particle size and total porosity. The main structural modifications observed were the cracking of the surface, particles aggregation/disaggregating and opening/closing of pores and/or cracks.

Soil Dynamics and Earthquake Engineering

Soil Dynamics and Earthquake Engineering

Lateral spreading of a submerged slope and validation of generalized scaling laws for LEAP-ASIA-2019

Geotechnical Earthquake Engineering and Soil Dynamics V, 2018

© 2018 American Society of Civil Engineers. Twenty-four centrifuge model tests have been conducte... more © 2018 American Society of Civil Engineers. Twenty-four centrifuge model tests have been conducted at nine different geotechnical centrifuge facilities around the world as part of the international LEAP effort (liquefaction experiments and analysis projects). All of the centrifuge models represent a 4 m deep 5 degree sloping submerged sand deposit. The mean effective PGA of the input motion for all of the experiments was approximately 0.15 g and the mean relative density was approximately 65%, but the effective PGA's varied between about 0.07 g and 0.3 g, and the relative densities varied between about 40% and 75%. The test matrix was designed to enable experimental quantification of not only the median response but also the trend and sensitivity of the model response to density and shaking intensity. Quantification of the sensitivity of the response to initial conditions is a prerequisite for objective evaluation of the quality of the model test data. In other words, a discrepancy between two experiments should be evaluated after accounting for the uncertainty in the initial conditions and the sensitivity of the response to initial conditions. For the first time, a sufficient number of experiments has been performed on a similar problem to provide meaningful quantitative evaluation of the trend between PGA, density, and displacement. The sensitivity is quantified by the gradient of the trend and the uncertainty of the trend is quantified from the residuals between the fitting data and the trend.

Soil Dynamics and Earthquake Engineering, 2012

Seismic behavior of inclined piles has been considered detrimental for years. However, recent res... more Seismic behavior of inclined piles has been considered detrimental for years. However, recent researches show that battered piles can have a beneficial effect. In this framework, a series of centrifuge tests on an inclined pile group is performed. The analysis is based on the comparative response of two 2 Â 1 simplified pile groups: one with vertical piles and the other with one vertical and one inclined pile. The response of these pile groups to repeated earthquakes or sinusoidal inputs is analyzed through the response frequencies, the envelop curves of bending moment profiles, the axial loads measured in both piles and the kinematic response of the cap. Results highlight that the effect of inclined pile is highly influenced by the frequency content of the input. In addition, the inclined pile induces non-negligible residual bending moments, higher horizontal stiffness at the pile cap and larger rotation.

Proceedings of the Sixth International Conference on Physical Modelling in Geotechnics, 6th ICPMG '06, Hong Kong, 4 - 6 August 2006, 2006

The SELFRAC project aimed to study the fractures within the Excavation Damaged Zone (EDZ) around ... more The SELFRAC project aimed to study the fractures within the Excavation Damaged Zone (EDZ) around galleries in the Boom clay and Opalinus clay formations and their possible sealing/healing with time. Tests carried out at LMR-EPFL aimed at quantifying on the same sample the increase in permeability induced by a localised crack, and subsequently the potential self-sealing process of this localised crack. The tests were performed in triaxial cells on hollow cylindrical samples and consisted in radial permeability measurements before and after the tensile fracturing of the clayey samples. In both clays, sealing processes are observed. However, the reduction in hydraulic conductivity after fracturing is much slower in Opalinus clay than the one in Boom clay (extremely fast recovering of the virgin clay permeability).

Note: Roches Reference LMR-REPORT-2005-001 Record created on 2006-11-09, modified on 2017-12-10

Bulletin of Earthquake Engineering

ABSTRACT Cet article rappelle les lois de similitude applicables en centrifugation, décrit la cen... more ABSTRACT Cet article rappelle les lois de similitude applicables en centrifugation, décrit la centrifugeuse géotechnique et le simulateur de séismes acquis par le LCPC (Laboratoire Central des Ponts et Chaussées) en 2006. Il présente également les nouveaux équipements développés pour réaliser les essais sismiques, en particulier le conteneur laminaire de type 'Equivalent Shear Beam' conçu pour simuler une masse infinie de sol avant liquéfaction.

Sont presentes trois nouveaux equipements de recherche experimentale dans le domaine sismique en ... more Sont presentes trois nouveaux equipements de recherche experimentale dans le domaine sismique en macro-gravite, implantes dans la centrifugeuse du Laboratoire Central des Ponts et Chaussees (LCPC Nantes). Le simulateur de seismes ID permet d'appliquer, soit un sinus a la base du modele, soif un seisme reel a contenu large bande. L'originalite de ce simulateur tient dans le mouvement reciproque de la charge utile et des contrepoids limitant la transmission des vibrations a la centrifugeuse. Les premiers resultats de la simulation d'un seisme sont presentes. Le second equipement est le conteneur laminaire de type ESB (Equivalent Shear Beam). Le troisieme est une centrale d'acquisition haute frequence.

International Journal of Heat and Mass Transfer, 2004

... F. Homand, A. Giraud Corresponding Author Contact Information , E-mail The Corresponding Auth... more ... F. Homand, A. Giraud Corresponding Author Contact Information , E-mail The Corresponding Author , E-mail The Corresponding Author , S. Escoffier 1 , A. Koriche and D. Hoxha. ... First approach explicit or semi-explicit solutions for the direct problems are used. ...