Numerical modeling of progressive rock fracturing and crack propagation under cyclical environmental forcing using thermally activated damage laws

Project description
The environment (meteorological and climatic conditions) is known to play a key role in rock erosion within the critical zone (the first few tens of meters of the subsurface). Cracking and fracturing in this critical zone is crucial in landform buildings, but also in gravitational natural hazards (rockfalls, landslides).

The sources and dynamics of fracturing on natural rock outcrops and cliffs remain insufficiently documented, and a quantitative estimation of environmental forcing on crack production is missing. Field and laboratory observations demonstrate the role of daily thermal cycles, rain, freeze and thaw cycles on progressive rock damage and furthermore rock erosion, but the physics behind is insufficiently quantified.

Goal of the internship
During this project we will adapt a numerical model describing thermally activated damage development in solid materials to the case of cyclical loadings. We will for instance include explicitly the time in the numerical scheme, together with a free boundary surface and, if possible, a pre-existing crack. The goal of the project will be to evaluate how cyclical loadings will increase the size of the crack. Numerical results will be compared to field and laboratory observations.

Contact : Eric.Larose univ-grenoble-alpes.fr