Modelling blast wave propagation in a subsurfacegeotechnical structure made of an evolutive porous material

Abstract In this study, a coupled thermo-hydro-mechanical-chemical (THMC)-viscoplastic cap model is developed to investigate the characteristics of blast wave propagation in a fill mass made of granular material (cemented backfill, CB) that is undergoing cementation under different curing conditions. The THMC model allows to evaluate its behavior and the changes in the material properties of the cementing granular material during the curing process, with rigorous evaluation of the coupled THMC factors. The THMC model is then coupled with a modified viscoplastic cap model to capture the nonlinear and rate-dependent behaviors of CB under blast loading. All of the material properties of CB required for the modified viscoplastic cap model are obtained from the THMC model. To validate the model, experiments carried out in high columns and impact testing on hydrating cemented backfill, as well as blast wave propagation experiments on soil and cemented backfill are adopted and simulated. A good agreement is found between the experimental and simulated results. Finally, by applying the coupled THMC-viscoplastic cap model, the effects of curing time, cement content, stope (mine cavity) size, initial backfill temperature, and filling rate on blast wave propagation in backfill mass are investigated. The obtained results provide new insight into blast wave propagation in fill mass under field curing conditions.