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Welcome to the HAL collection
of GEOMAS Laboratory - Geomechanics, Materials, Structure


The GEOMAS laboratory (Geomechanics, Materials, Structure) is a research team (EA 7495) under the supervision of INSA Lyon.

The laboratory is located on the Lyon-tech la Doua campus in Villeurbanne and brings together professors and researchers from the Civil Engineering field, particularly in the fields of structural mechanics, materials and geomechanics.

The laboratory's objective is to conduct excellent academic research, with partnership-based research, aimed at meeting industrial and societal needs in the fields of construction in the broadest sense (geomechanics, materials and structures) in interaction with their environment.


Last publications


Reinforcement Transmission Out-of-plane loading BENTONITE Instability Composite coats Relaxed micromorphic model 74Q15 effective constitutive equations 1 Alexios Aivaliotis Wave propagation ARGILE Coupling Pullout test Micropolar Enriched continuum mechanics Micro-stretch model Generalized continua Rockfill structures Plastic hinges Hydratation Bounded stiffness Micro-void model Incremental response Band-gaps Rammed earth Endommagement Ciment riche en mayénite Oedometric compression Stiffness Ettringite binder Béton armé Corresponding author Damage Failure 74M25 micromechanics Masonry Cisaillement Modélisation Cement rich in mayenite Metamaterials Cinétique Micromorphic continuum Micro-strain model Characteristic length 74J05 linear waves Finite elements Second-order work Ciment alumineux Bifurcation Anchor Reflection Cosserat continuum Discrete element method Matériau granulaire Concrete Size-effect Finite element modeling Civil engineering 74J10 bulk waves Experiments Confinement Matériaux Méthode des éléments discrets CISAILLEMENT Impact Enriched continua Génie civil Wave-propagation BETON ARME Materials Subdomain decomposition Size effects 74A60 micromechanical theories Simulation numérique Rupture 74J20 wave scattering Jeune âge Gradient elasticity Plasticity Moving load Anisotropy Couplage Shear Contrainte mécanique Hydration Stirrups 75J15 surface waves Granular material Grain breakage Chape autonivelante Modeling Reinforced concrete DALLE BRIQUE 74B05 classical linear elasticity SEDIMENT Couple stress model EXPERIMENTATION Interface Renforcement Fresh wood








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Actuality of laboratory

Soutenance de thèse de Lianxin HU


In order to model the behavior of geometarials under complex loadings, several researches have done numerous experimental works and established relative constitutive models for decades. An important feature of granular materials is that the relationship between stress and strain especially in elastic domain is not linear, unlike the responses of typical metal or rubber. It has been also found that the stress-strain response of granular materials shows the characteristics of cross-anisotropy, as well as the non- linearities. Besides, the stress-induced anisotropy occurs expectedly during the process of disturbance on soils, for example, the loads or displacements. In this work, a new model which is a combination of Houlsby hyperelastic model and elastoplastic Plasol model was proposed. This new model took into account the non-linear response of stress and strain in both elastic and plastic domain, and the anisotropic elasticity was also well considered. Moreover, the overflow problems of plastic strain in plastic part was calibrated by a proper integration algorithm. Later, new model was verified by using numerical method and compared with laboratory experiments in axisymmetric triaxial conditions. The comparison results showed a good simulation effect of new model which just used one single set of parameters for a specific soil in different confining pressure situations. Then the analysis of new model internal variable, i.e., pressure exponent, illustrated that the value of pressure exponent which corresponds to the degree of anisotropy had an obvious effect on the stress-strain response. Moreover, this kind of effect is also affected by the density and drainage condition of samples. Basing on new model, a safety factor which refers to the second-order work criterion was adopted and tested in axisymmetric model and actual slope model. It showed that the negative value or dramatic decreasing of global normalized second-order work occurs accompanying with a local or global failure with a burst of kinetic energy.

Date Publication: 
Mercredi, Décembre 16, 2020

Liaxin a soutenu sa thèse "Micromechanics of Granular Materials During Complex Loadings", le 15/12/2020 (en visio), sous la direction de A. Daouadji et F. Prunier. Felicitations à lui!

Soutenance de thèse de Danai Panagiota TYRI


Soutenance de thèse de Chaimaa Jaafari




Angela Madeo, Pr. à GEOMAS, lauréate d'une ERC