  This paper presents an extension of the discrete element method using a
phase-field formulation to incorporate grain shape and its evolution. The
introduction of a phase variable enables an effective representation of grain
geometry and facilitates the application of physical laws, such as
chemo-mechanical couplings, for modeling shape changes. These physical laws are
solved numerically using the finite element method coupled in a staggered
scheme to the discrete element model. The efficacy of the proposed Phase-Field
Discrete Element Model (PFDEM) is demonstrated through its ability to
accurately capture the real grain shape in a material subjected to dissolution
only and compute the stress evolution. It is then applied to model the
phenomenon of pressure solution involving dissolution and precipitation in
granular materials at the microscale and enables to reproduce the creep
response observed experimentally. This framework contributes to the enhanced
understanding and simulation of complex behaviors in granular materials and
sedimentary rocks for many geological processes like diagenesis or earthquake
nucleation.
