Geomechanics

IMMC

The research activities in the Geomechanics team at UCLouvain deal with the mechanical behavior of geomaterials subjected to thermo-hydro-chemo-mechanical couplings, developing constitutive laws, experimental methods and advanced numerical models for the understanding and modeling of :

Energy infrastructures (Offshore wind turbine foundations, geothermal energy, or hydrogen storage)
Geohazards (landslides, earthquakes, volcanoes collapse)

Link to Hadrien Rattez's personal page (biography, teaching, research, publications)

Researchers
• PhD students : Maxime Delvoie, Jens Niclaes, Nathan Delpierre, Alexandre Sac-Morane, Tamara Wehbe, Saad Mortadi, Hossein Shahabi
• Senior scientists / postdoc researchers : Luc Simonin, Shijin Li

Stability of volcanic and embankment slopes

A landslide is the mass movement of earthen materials induced when the soliciting forces (mainly gravitational) overcome the shear resistance inside a geomaterial. This phenomenon can often lead to devastating impacts including loss of human lives, damage to critical infrastructure and disruption to livelihoods. Our research focuses on better understanding the triggering mechanisms of landslides in different contexts.

The intensifying effect of climate change will give rise to extreme rainfall events, accompanied by floods causing the saturation and overtopping of embankments, which can lead to their slope failure. These rainfalls can also cause an increase of water-triggered landslides especially in steep topographies like volcanoes. Finally, hydrothermal alteration inside volcanoes can weaken the rocks and promote large catastrophic flank failures, like in Mount Saint Helens (USA) in 1980.

Wind turbines foundations.

The widespread deployment of offshore wind turbines in Europe requires the use of economic and sustainable foundation systems. The objective of our research is to develop a better understanding of the soil-structure interaction during the installation and operational use of the foundation . We study an alternative method to the traditional impact driving for monopile installation, namely vibratory driving. We develop model experiments in a centrifuge, large-scale experiments, and numerical dynamic large deformation models. Additionally, we study the evolution of the mechanical response of the foundation system during the lifetime of the wind turbine to optimize its design and its decommissioning.

Fault Mechanics

Earthquakes are destructive natural hazards caused by instabilities along pre-existing faults. They can be triggered naturally or induced by human activities (geothermal projects, CO2 storage, etc…). Our goal is to study the physical mechanisms at the origin of their triggering and propagation. Indeed, fault zones are complex multi-scales structures that host numerous processes like strain localization, rock damage, large temperature increases or phase changes (like melting of the rock). We aim at better capturing those mechanisms numerically or experimentally.

Micro-mechanics of Geomaterials

To better understand and predict the mechanical behavior of soil and rocks subjected to long-term evolutions or extreme conditions difficult to reproduce in the laboratory, our aim is to develop a fundamental understanding of the mechanisms at micro and nano- levels.
Experimentally, we combine imaging techniques like X-ray computed tomography or Scanning electron microscopy to mechanical tests. This combination allows to observe experimentally the microstructure evolution of the material when deforming.
Numerically, we use models based on the discrete element methods to study grain rearrangement, the phase field method or reactive transport modelling to investigate the microstructure evolution in a chemically active environment and how it influences the mechanical behavior.