Abstract:Chalk is a typical material with high porosity. The experimental results suggest that the chalk behavior can be modeled in terms of elastoplastic model with two plastic deformation mechanisms:plastic compaction (pore collapse) and plastic shearing. Porosity plays an important role in the chalk plastic behavior. In other words,the effect of porosity needs to be taken into account in the modelling of chalk plastic behavior,especially in the modelling of chalk plastic compaction. Based on the concept,a new constitutive model,which is based on the Gurson criterion,is proposed for the description of plastic compaction behaviors in porous chalks. In general,the model predictions are in satisfactory agreement with the experimental results.