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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


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








Deposits by type of document

Evolution of deposits




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