Abstract: Explosive seismic waves, characterized by long wavelengths, strong amplitudes, and rapid propagation speeds, constitute the primary factors inducing secondary disasters such as building collapses and infrastructure damage. Based on two typical explosion-proof equipment, static explosion tests with varying TNT charges were conducted to investigate the propagation and attenuation patterns of explosive seismic waves under three distinct protective conditions: free-air blast (FAB), steel explosion-proof (SEP), and flexible explosion-proof (FEP). The time-domain response of vibration velocity and dominant frequency characteristics of SEP and FEP were analyzed. The study found that the vector sum of triaxial peak vibration velocities increases with the TNT quantity and decreases with the explosion distance. Conversely, the triaxial dominant frequencies do not exhibit significant changes with increasing explosion distance or TNT quantity. Compared to FAB, both SEP and FEP exhibit significant protective performance against the triaxial peak vibration velocities of explosive seismic waves. A decay model for the vector sum of triaxial peak vibration velocities under SEP and FEP protection was established, which subsequently facilitated the classification of building damage levels into three criteria: safe, slightly damaged, and severely damaged. These findings provide valuable references for the structural design of related blast-proof equipment and the evaluation of protective effectiveness against explosive seismic waves.

Key words: explosion seismic wave, vector sum of triaxial peak vibration velocities, dominant frequency, blast-proof equipment, protective performance