Stemming Column Phenomenology

摘要

Cliff Olsen (LLNL) has reported measurements of unusual stress-time behavior in the stemming column of a nuclear event. Following the dynamic stress peak, he sees a second stress peak whose amplitude sometimes exceeds the dynamic pulse. We have seen a similar phenomena in grouted drill holes which stem 64-lb high explosive events. Although we have not explained the phenomena, we offer the following hypothesis. The stemming materials responds differently than the host material to the unloading and rebound dynamics that occur with the formation of the residual stress field. We challenge the calculation community to model and predict this phenomena, for understanding it may lead to potentially useful stemming techniques. 2 refs., 2 figs. (ERA citation 12:048298)