SEISMIC IMAGING OF BLAST DAMAGE

Two case studies are described where seismic tomographic imaging techn iques have been used to map blast induced damage zones. In the first c ase, the detonation of 22 kg of a high energy explosive created a zone of decreased P-wave velocity, which was preferentially extended along nearby joints. The second case study involved evaluating blast induce d damage in a surface crown pillar, which shows a zone of reduced velo city directly caused by rock mass deterioration associated with the un derlying excavation geometry. In situ imaging of blast damage may prov ide useful information for blast monitoring to characterize the damage zone, to verify blast damage models, and to optimize blasting strateg ies.