Understanding the threat posed by buried charges in different operating environments

When an explosive device is buried in soil, it creates a risk to the safe passage of people and vehicles in the area. Buried explosives have been used extensively in warfare for many years, including their use for area denial with minefields, Improvised Explosive Devices (IEDs) and cluster munitions. This work does not consider the doctrine or ethics of the use of explosives in warfare, instead it aims to investigate the impact that the burial conditions of existing explosive remnants of war has on the threat they pose. This has been an active research area for many decades, with numerous teams undertaking research to investigate the impact of different geotechnical parameters. This work extends the existing knowledge to explore new areas of interest both from a geographical and geotechnical point of view. Data has been gathered on three new environments: sub-arctic frozen soil; littoral environment with a varying water table; and carbonate-based soils.

Explosive testing has been conducted at the University of Sheffield's Blast and Impact Dynamics Laboratory, using the Characterisation of Blast Loading test apparatus to measure the specific impulse and total impulse generated by charges buried in different soil conditions. These results have been compared to historical data and conclusions drawn on the risk posed by the newly explored environments.

The results found that the existing standards employed by NATO forces in the design of blast resistant vehicles is likely to be a conservative standard, with all of the testing conducted being of a lower (or equal) threat to that covered by the NATO standards. Of the three environments considered, the variable water table within the soil was found to have the largest impact on the above ground blast loading. Conversely, testing in carbonate sand was found to produce a loading very similar to the historic testing with quartz-based sand. Finally, testing in frozen soil was found to be significantly more variable, with a higher loading than its non-frozen counterpart.