Hypoplastic modelling of moisture-sensitive weathered rockfill materials

For broken rock materials under stress the process of weathering and consequently the degradation of the solid hardness may be accelerated under water. Thus, the resistance of particles against abrasion and breakage can be strongly influenced by a change of the moisture content of the grains. The focus of this paper is on modelling the essential mechanical properties of moisture-sensitive weathered coarse-grained rockfill materials using a hypoplastic constitutive model. The model takes into account the current void ratio, the effective stress, the strain rate and a moisture-dependent degradation of the solid hardness. Creep and stress relaxation during the process of degradation of the solid hardness are also included. It is shown that the results obtained from numerical simulations are in good agreement with experiments carried out with weathered granite.