Repeatability of buried charge testing

The relationship between the geotechnical parameters and the impulse delivered by a charge buried shallowly (<100 mm) within a soil mass has received much attention in recent times. It has previously been demonstrated that for uniform soils a high degree of repeatability in the delivered impulse can be achieved when carefully controlling the geotechnical conditions. In this paper the authors explore the recommendations given in AEP55 regarding the testing of surrogate mine blasts using both minepots and the STANAG standard sandy gravel. With moisture content and bulk density being intrinsically coupled, using bulk density as a measure of geotechnical control and hence repeatability is questionable. A methodology for the careful preparation of the Stanag sandy gravel soil is presented along with comparative results from minepots demonstrating the comparative repeatability of both methodologies. These results are then compared with a number of other soils to allow gen-eral conclusions about the repeatability of specific soil characteristics to be drawn.