Numerical and experimental investigation and modelling of coupled chemo-hydro-mechanical degradation processes in soft carbonatic rocks

Short term visitor's project

The project aims at developing an innovative, state-­of-­the-art approach for the description of the effects of chemical weathering processes of weak natural rocks such as sandstones and calcarenites subject to “environmental loading” conditions. Depending on the mineralogy of the intact rock, weathering process can affect existing interparticle “bonds”, as well as induce a progressive degradation of the solid skeleton itself, as observed, for example in calcarenite rocks from the Apulia region (e.g. Ciantia 2013, Ciantia & Hueckel 2013). To this end, the project is developed along two parallel and strongly interacting lines:

• the use of advanced experimental techniques such as micro X-­‐ray and Neutron Computed Tomography (XCT, NCT) and associated image analysis techniques to obtain detailed information at the microscale on the physics of chemo-­‐mechanical degradation processes in cemented calcareous sands, with particular reference to: i) the study of the temporal and spatial distributions of the chemical degradation induced by the propagation of an acid font; ii) the grain-­‐scale investigation of chemo-­‐mechanical bond degradation processes; iii) the microscale investigation of grain dissolution processes and the quantitative link between grain dissolution and chemically-­‐induced macroscopic deformation of the porous medium.

• the development of a suitable constitutive model in the framework of the theory of plasticity with extended hardening laws. To overcome the limitations of the purely macroscopic approach and to exploit fully the microstructural information provided by XCT and NCT, the development of the model will follow the principles of multiscale modeling.