GHASSAN SHAHIN -

I am a geomechanics researcher with interests in exploring the mechanical behavior of Earth's materials under conditions relevant to the shallow Earth and upper mantle. In my studies, I utilize laboratory geomechanics and x-ray techniques as well as advanced constitutive modeling and material instability theories.

I currently serve as a Marie Curie EPFLeaders4Impact Postdoctoral Fellow at the Swiss Federal Institute of Technology in Lausanne. I was a postdoctoral fellow at the Johns Hopkins University Department of Mechanical Engineering. I hold a Ph.D. in Civil and Environmental Engineering from Northwestern University, a joint Erasmus Mundus master's in Earthquake Engineering from the University of Grenoble-Alpes and the School of Advanced Studies-Pavia, and a B.S. in Civil Engineering from Damascus University.

EPFLRock4CCS: Quantifying chEmo-hydromechanical Properties and FaiLure mechanics of reservoir ROCKs for Carbon Capture and Sequestration

Geological sequestration of CO2 involves high pressure injection of liquids deep underground in porous reservoirs covered by layers of impermeable cap rock. Such operations may induce stress and chemical perturbations and even cause irreversible deformation in and around injection formations. Creation of new fractures or the reactivation of existing faults may occur. Collapses leading to pores closure and deterioration in reservoir productivity may also occur. Here, via a laboratory pilot study, mimicking injection into a reservoir on a miniature scale, we will characterize, through a multi-scale approach, the effect of pressurized water and weak acids on yield and ultimate strengths of porous rocks.

This project supports a range of the United Nations Sustainable Development Goals, specifically Affordable and Clean Energy, Climate Action, Sustainable Cities, and Responsible Production and Consumption. This project is funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Fellowship and the Swiss Federal Office of Energy. The project bridges collaborations between EPFL and Ecole Normale Superieure-Paris, Ecole des Ponts, and the Johns Hopkins University bringing together expertise in geomechanics, geosciences, and geotechnology.

University of Grenoble-Alpes

Micromechanics and Strain Localization in Sand in the Ductile Regime

Physical investigations based on in-situ x-ray tomography of grain-scale processes (grain-breakage and contact frictional sliding) conducive for yielding and compaction localization in sand deformed in the ductile regime

Quantifying the hierarchy of structural and mechanical length scales in granular systems

Based on x-ray tomography and x-ray diffraction measurements of stress and strain in granular systems, this fundamental study of the transition from heterogeneous to homogenous scale reveals scales hierarchy in geometry, stress and energy dissipation

HP-TACO: A high-pressure triaxial compression apparatus for in situ x-ray measurements in geomaterials

Technical paper reporting, with demonstrations, features of a new load-frame designed by the Authors and installed at Johns Hopkins University to test geomaterials under high pressures with the aid of in-house and synchrotron x-ray tomography.

The Role of Stratigraphy and Loading History in Generating Complex Compaction Bands in Idealized Field‐Scale Settings

Numerical investigations into the origin, causes, and sequences of complex compaction band structures in the dessert of Utah, combining geological history, field stratigraphy, material theories, and finite element computations.

Experimental study of compaction localization in carbonate rock and constitutive modeling of mechanical anisotropy

Laboratory investigation combined with theoretical developments to explain the divergent anisotropic responses in yielding-stresses and post-yielding deformation in the highly porous rock of Maastricht Tuffeau.

Simulation of emergent compaction banding fronts caused by frictional boundaries

The role of boundary effects in promoting heterogeneous deformation fields is assessed in the context of examining the bias that boundary friction could introduce on the characterization of compaction localization in predominantly softening and hardening porous rocks.