The stopes left after underground ore extraction are sometimes filled with a mixture of recycled full stream tailings, mine process water and a hydraulic binder agent such as cement. This material is usually known as cemented paste backfill (CPB) and has gained great popularity in underground operations in the recent past. In order to retain the fill inside the stope a barricade is constructed across the access drive. These stopes are usually subjected to blast loading resulting from the extraction of contiguous ore body. Understanding the dynamic response of the stopes at early curing ages may improve the design and performance of barricades thus preventing, in extreme cases, their structural collapse and the consequent inrush of fresh CPB to mining areas. In this article, simulations are carried out on a backfilled stope subjected to blasthole explosions using the explicit nonlinear FE code LS-DYNA. To account for the pore water pressure build-up within the fill, a suitable soil model available in LS-DYNA was chosen. In the first part of this article, the propagation of stress waves through rock was studied and results compared to experimentally obtained scaling laws for site specific conditions. In the second part, the effects of single blasthole detonation, and its proximity to the stope, on the total horizontal stress exerted by the fill on the barricade was researched. In addition to this, the blast-induced liquefaction potential of CPB was also numerically examined.