ABSTRACT
We have developed a new microscale mechanical-chemical (MC) model that accounts for coupled deformation, dynamic contacts, and reactive transport in granular systems with realistic geometric representations. The MC model was achieved by linking a new microscale mechanical code based on the numerical manifold method (NMM) to the reactive transport model Crunch. Using this first of its kind quantitative microscale model, we show the results of compaction and pressure solution within a halite aggregate. We found that sharp corners of salt grains can dominate the contact dynamics, microfracturing, and pressure solution during the compaction, and thus govern the structural changes and porosity loss of the system. We found that pressure solution, which preferentially dissolves sharp corners and edges, can lead to relatively high porosity loss in the system, thus playing an important role in the creep of salt. Our analysis showed that the dynamic changes of salt granular systems involving grain relocation and pressure solution can occur repeatedly and continuously, thus contributing to longer-term creep of salt at larger scales.
