Centrifuge Characterization of Buried, Explosive-Induced Soil Ejecta Kinematics and Crater Morphology

Abstract

A comprehensive experimental regime was conducted to advance the understanding of the mechanistic phenomena of buried, explosive-induced soil responses using geotechnical centrifuge modeling. To address experimental gaps in the current literature, this research documents the high-rate dynamic soil behavior under explosive loads with parametric variations of charge size, burial depth, and g-level in conjunction with post-detonation static measurement of blast-excavated craters. The novel integration of a high-speed imaging system into the centrifuge domain, placed in close proximity to the blast, enabled a rigorous in-flight characterization of the transient, multiphasic soil blast mechanics including early soil disaggregation, gas–particle interactions, and soil dome evolution. The results indicate that initial soil surface motions appear progressively later, post-detonation, with elevated acceleration. Furthermore, the data demonstrates that gravity-induced confining stresses reduce the temporal and spatial soil disaggregation flow kinematics. Crater dimensions, measured by a laser profilometer, also exhibit a gravity-dependent decrease and a new, dimensionless coupling function correlates the physical ejecta dynamics to the crater dimensional statics evident in the buried blast phenomena. An in-depth analysis compares this study’s empirical scaling relationships in both dimensional and dimensionless form to a compilation of past field and centrifuge results and demonstrates their favorable correlation to full-scale explosive events. The high-fidelity, repeatable database establishes a benchmark for future parametric experimental investigations and provides a physical basis for calibration and validation of computational simulations of soil blast mechanics including soil deformation and ejecta flow.