A method for measuring the impulse on structural foundations due to a blast wave

Diaphragm gauges were developed in order to measure blast impulses. These gauges can be used to measure blast in air, water, soil and other environments. Such instrumented gauges were used in blast tests of the Israeli Home Front Command that were conducted in January, 2008. In these tests, the diaphragms were positioned on the foundations of a structure, in front of which hemispherical TNT bare charges were detonated at various distances. Measurement results were collected and analyzed (strain commencement times, residual strains, and final central deflections) in order to gather data on the blast impulses acting on the structural foundations under various conditions. It was found that under the conditions of the present experiments (measurement on shallow buried foundations), the major factor determining the level of the impulse on the structural foundations is the ground blast wave induced by the air blast wave. In particular, the impulse load on the buried structure was much greater when there was an above-ground structure above it, from which the blast wave reflected into the soil.