Large-Scale Field Experiments on Blast-Induced Vibration and Crater in Sand Medium

Blast-induced craters and ground vibrations caused by underground explosions are the foundation of explosion-resistance design for underground structures and protective facilities. In this study, large-scale blast experiments were performed in the field to investigate the characteristics of the ground vibrations and craters induced by single underground explosions in a loose, wet sand medium. Results from eight single blasts with emulsion explosives ranging from 200 to 400g and buried depths ranging from 0.5 to 1.0 m are presented in this paper. A numerical simulation for Blast E8 using the coupled smoothed-particle hydrodynamics and finite-element method (SPH-FEM) is also presented. The influences of charge weight and buried depth on blast-induced crater formation and ejecta shape were studied. The experimental data for crater diameter were found to be roughly identical to the results suggested for wet sand. An empirical fitting formula for the ground vibration induced by single underground explosion in a loose, wet sand medium was developed using the vertical and radial components of peak particle velocity (PPV) obtained from the experiments. A numerical simulation using a coupled SPH-FEM was modeled to validate the experimental results and prove the method's ability to model the blast-induced crater and ground vibration.