Effect of explosive cratering on embankment dams

The efficient management and protection of critical infrastructure such as dams is relevant to safety of the population of low-lying downstream communities. Ramifications of dam breach on these communities would be severe and include loss of electricity, flooding, injury and fatality. The economic losses can be enormous depending on the size of the dam and level of emergency preparedness of the community. As acts of terror continue to increase globally, dams appear to be attractive targets due to the capacity to adversely impact downstream communities and to attract media attention. Embankment dams are more susceptible to cratering and, in turn, overtopping and erosion of the dam crest. This paper investigates the effects of explosions on embankment dams by using a high-fidelity physics-based numerical analysis software program -LS-DYNA. The impacts of explosive size, reservoir level and soil density were examined while measuring the dimensions of the resulting crater. The investigation showed that an increase in explosive size led to an increase in crater diameters as well as the depth. In considering the reservoir level, the reservoir was considered at maximum capacity, at mid-capacity and embankment without a reservoir. The results showed that the crater dimensions were larger at maximum capacity and lowest when there was no water in reservoir. At a given soil density, when the dam fill materials are saturated, the crater dimensions are larger in terms of diameters and depths as compared to when fill materials are not saturated.