Publications by Laurent Vulliet

Numerical modeling and neural networks to identify model parameters from piezocone tests: II. Multi-parameter identification from piezocone data

Laurent Vulliet, Andrzej Truty, Rafal Filip Obrzud

This paper completes the study presented in the accompanying paper, and demonstrates a numerical algorithm for parameter prediction from the piezocone test (CPTU) data. This part deals with a development of neural network (NN) models which are able to map ...

Wiley-Blackwell2012

Numerical modeling and neural networks to identify model parameters from piezocone tests: I. FEM analysis of penetration in two-phase continuum

Laurent Vulliet, Andrzej Truty, Rafal Filip Obrzud

This study presents a numerical approach designed for material parameter identification for the coupled hydro-mechanical boundary value problem (BVP) of the piezocone test (CPTU) in normally and lightly overconsolidated clayey soils. The study is presented ...

Wiley-Blackwell2011

Analytical and numerical analyses of the load-bearing capacity of retaining walls laterally supported at both ends

Laurent Vulliet, Sylvain Plumey, Vincent Labiouse, Aurelio Muttoni

This paper investigates the load-bearing capacity of a perfectly smooth retaining wall laterally supported at both ends assuming that the wall fails by the development of three plastic hinges. The study considers the case of a cohesionless elastic–perfectl ...

Wiley-Blackwell2011

Structural characterization of unsaturated aggregated soil

Lyesse Laloui, Laurent Vulliet, Azad Koliji

Despite the recent experimental studies of soil structure, a comprehensive understanding of the macroscopic response of a soil in relation to its structure has not yet been achieved. This lack of understanding reveals the need for further assessments of so ...

2010

Constitutive modeling of unsaturated aggregated soils

Lyesse Laloui, Laurent Vulliet, Azad Koliji

A coupled water retention-mechanical constitutive model for unsaturated aggregated soils is presented here. Based on the multi-scale experimental results, the model incorporates the inter-particle bonding, fabric and partial saturation effects in a single ...

2010

A combined neural network/gradient-based approach for the identification of constitutive model parameters using self-boring pressuremeter tests

Laurent Vulliet, Rafal Filip Obrzud

This paper presents a numerical procedure of material parameter identification for the coupled hydromechanical boundary value problem (BVP) of the self-boring pressuremeter test (SBPT) in clay. First, the neural network (NN) technique is applied to obtain ...

2009

Identification of mechanisms for landslide type initiation of debris flows

Lyesse Laloui, Laurent Vulliet, Georg Klubertanz

The modelling of debris flow initiation in slopes is addressed in this paper. First, possible factors governing debris flow initiation are established. Then, a coupled hydro-mechanical model for deformable porous media with two pore fluids that is used to ...

2009

Characterization of natural sand under complex dynamic loading

Laurent Vulliet, Emilie Rascol

An experimental study, conducted with an advanced triaxial press, evaluates the effect of different loading paths on the dynamic behavior of natural Swiss sand. Emphasis is put on comparison between the dynamic parameters evaluated in a single loading (wit ...

Taylor & Francis Group2009

Optimization framework for calibration of constitutive models enhanced by neural networks

Laurent Vulliet, Rafal Filip Obrzud

A two-level procedure designed for the estimation of constitutive model parameters is presented in this paper. The neural network (NN) approach at the first level is applied to achieve the first approximation of parameters. This technique is used to avoid ...

2009

Behavior of Unsaturated Aggregated Soil in Oedometric Condition

Lyesse Laloui, Laurent Vulliet, Azad Koliji

Natural and agricultural soils usually possess an aggregated structure; in the sense that they are composed of aggregates and large inter-aggregate pores. Under the natural condition, these soils are usually unsaturated and the large pores are easily drain ...

2009

Assessment of structural evolution of aggregated soil using neutron tomography

Lyesse Laloui, Laurent Vulliet, Azad Koliji

The advanced non-destructive method of neutron tomography, together with image analysis, is used to evaluate the structural evolution of an aggregated soil during one-dimensional compression tests. Aggregation of primary particles is a commonly observed ph ...

American Geophysical Union2008

New basis for constitutive modelling of unsaturated aggregated soil with structure degradation

Lyesse Laloui, Laurent Vulliet, Azad Koliji

CRC Press2008

Advanced Constitutive Model for Unsaturated Structured Soil with Double Porosity

Lyesse Laloui, Laurent Vulliet, Azad Koliji

2008

New basis for the constitutive modelling of aggregated soils

Lyesse Laloui, Laurent Vulliet, Azad Koliji

Natural and compacted soils are usually characterized by aggregation of particles. The mechanical behaviour of these materials depends on soil structure. The oedometric compression tests performed on aggregated samples presented here showed that these mate ...

Springer-Verlag2008

Water flow between soil aggregates

Lyesse Laloui, Laurent Vulliet, Azad Koliji

2007

Automated Digital Image Processing for Volume Change Measurement in Triaxial Cells

Lyesse Laloui, Laurent Vulliet

An automated digital image processing technique is presented for the measurement of specimen volume change during triaxial testing. A digital camera is fixed at a constant distance from the triaxial cell. Pictures taken at various intervals are processed ( ...

2007

Soil structure evolution : experimental and constitutive consideration

Lyesse Laloui, Laurent Vulliet, Azad Koliji

2007

Experimental and numerical investigations of the behaviour of a heat exchanger pile

Lyesse Laloui, Laurent Vulliet, Mathieu Nuth

2006

Attrition and particle breakage under monotonic and cyclic loading

Lyesse Laloui, Frédéric Mayoraz, Laurent Vulliet

2006

Elasto-plasticity of unsaturated soils : laboratory test results on a remoulded silt

Lyesse Laloui, Laurent Vulliet

Current models of the elasto-plastic behaviour of unsaturated soils contain important underlying assumptions that have not been tested due to a lack of adequate experimental data. To address this issue, the objective of this paper is to provide a comprehen ...

2006