The ALERT Workshop 2024 should be held in Aussois from 30th September to 2nd October, 2024. Abstracts can now be submitted for the sessions. Please submit your abstracts by email directly to the coordinators using the Workshop abstract form (doc). If you wish to publish your presentation after the Workshop on the ALERT website, do not forget to agree by ticking the corresponding box in the abstract form.
Since time for the presentations is limited, only a part of the submitted abstracts can be chosen for the oral presentations. Therefore, we invite you to submit your abstract as soon as possible. The presentation can also be submitted as a poster. The abstracts of the posters will be published in a separate booklet (ISSN registered).
The deadline for the abstract submission is May 24, 2024. For any communication about your participation to the workshops, please contact the coordinators of the workshop sessions directly.
Here is a reminder of the workshop sessions that are opened to abstract, as well as a short description of each of them:
- Session 1: “Emerging properties in geomaterials across the scales”
Organizers: Antoine Wautier, Farhang Radjai and Francesco Froiio.
Geomaterials exhibit a wide range of complex behaviors that are of crucial interest for engineering scale applications or for mitigating natural risk hazards. Such behaviors are often accounted for through continuum mechanics concepts such as constitutive behavior, yield surfaces, hardening law, permeability, shear or compaction bands… Given the complexity of the macroscopic behavior of geomaterials, a current strategy is to use a multi-scale approach either in the lab or in the virtual lab (with DEM, molecular dynamics, X-ray tomography, SEM…), to identify sub-components with simpler behavior. However, in the change of scale, some properties are lost and some emerge.
In the upscaling, we face the issue of emerging properties fundamentally different from those at lower scales. For instance, sand is usually modeled as non-deformable solids interacting through elastofrictionnal contact laws, but the internal friction angle (macroscale) does not corresponds to the contact friction (micro scale) but incorporate geometrical properties of the microstructure.
On the contrary, the huge number of degrees of freedom that exist at the microscale is compressed into a much more limited number of macroscopic degrees of freedom. For instance, the displacements and the rotations of thousands of sand grains reduce to the strain tensor (and possibly its derivatives for enriched continuum mechanics) at the representative elementary volume scale. For the stress, the well-known Love-Weber formula, compress contact based information into a second order tensor.
Working on the mico to macro link is probably the key for a wise use of phenomenological constitutive models (e.g. physics based justification of the parameters) and for an efficient use of multiscale strategies (e.g. FEMxDEM methods save probably too much microscale information).
In addition, fundamental knowledge on the micro/macro link may prove crucial to anticipate future use of geomaterials subjected to unprecedented loading conditions. Among other conditions, we can think of temperature rises, thawing permafrost, chemical creation or dissolution of bonds, diffusion of pollution, cyclic loadings, recycling materials, varying degrees of saturation…
- Session 2 (half-day): “Geomechanics at the submicron-scale”
Organizers: Katerina Ioannidou and Gilles Pijaudier-Cabot.
Geomaterials usually exhibit complex mechanical behavior across several length and time scales. The submicron scale is relevant for understanding the microstructure and mechanical response of various geomaterials such as rocks, soils, sediments etc. Such materials are usually porous or granular and have been formed under different environmental conditions. At the submicron scale, nanoscale effects become significant. This includes phenomena such as surface roughness, intermolecular forces, pore structure, and distribution of defects which can influence the mechanical behavior of geomaterials. Moreover, processes such as fluid flow through nanopores, adsorption and desorption of fluids on mineral surfaces, and chemical reactions at mineral-fluid interfaces are important for the formation and aging of the microstructure of geological materials.
This session aims to elucidate processes at the submicron scale either with numerical or experimental techniques that are important for geomechanics.
We invite contributions related to, but not limited to, the following topics:
– Multiscale modeling and simulations of geomechanical processes
– Fluid-solid interactions and nanopore-scale transport phenomena
– Nanoindentation and atomic force microscopy (AFM) studies of geological materials
– Microstructure characterization and imaging techniques at submicron scales
– Fracture mechanics and crack propagation in geomaterials
– Applications of submicron scale geomechanics in petroleum engineering, geotechnical engineering, environmental science, and materials science
– Experimental techniques and instrumentation for studying geomechanics at small length scales
– Advances in nanotechnology for geomechanical applications
- Session 3: “Continuum-based particle methods”
Organizers: Claudio Tamagnini, Lorenzo Sanavia, Matteo Ciantia and Antonia Larese.
Until relatively recently, most of the mathematical formulations proposed for modeling multiphysics geomechanical problems relied on the assumption of linearized kinematics, i.e., the deformation of the soil mass is sufficiently small such that the current and the reference configurations of the soil body are virtually indistinguishable. However, geometric non-linearity may play an important role in some practical applications. A number of important failure and flow problems are indeed characterized by significant changes in the soil mass geometry and very high deformation levels. A non-exhaustive list of practical applications which require both mechanical and geometrical non-linear characterization of soil behavior include: the evaluation of pile bearing capacity of offshore platforms; the modeling of subsidence phenomena associated to hydrocarbon extraction and sinkhole formation; the study of the effects of pile driving; the interpretation of cone penetration tests under undrained or partially drained conditions; the modeling of slow slope deformations in presence of significant modifications of the slope geometry. The workshop intends to bring together researchers working in these fields to provide an overview of a number of relatively recent numerical methods (for example: MPM, PFEM, Peridynamics, SPH) capable of dealing with extreme deformations as well as non-linear material behavior of the soil mass, still remaining within the realm of continuum mechanics of porous granular materials.