Underwater Explosion Bubble Jetting Effects on Infrastructure

Abstract : Underwater explosions present a significant risk to structures because they were not designed for these types of loads and because water transmits explosive energy much more efficiently than air. The US Navy demonstrated that the effect of bubble jetting from an underwater explosion can result in significant late-time loading compared to the initial shock loading. However, neither the effects of bubble jetting on structures, where the explosion is likely to be lateral to the target rather than beneath it, nor the loading conditions required to produce bubble jetting effects on such structures (charge weight, submerged depth, and standoff distance to structure) are well understood. This investigation improves characterizations of bubble formation, collapse, and jetting near lateral targets. The research includes very small-scale tests to observe bubble jetting, slightly larger underwater blast experiments to determine bubble jetting loads on vertical structures, and larger-scale experiments to measure bubble jetting effects on the structural deformation to structures.