Numerical analysis of secondary system subjected to underground blast loading

The vulnerability of secondary systems (SS) to seismic activities has become a critical area of research due to their potential for significant damage even under low-intensity seismic waves, particularly those caused by underground blast induced ground motion (UBIGM). Unlike the extensively studied Primary System (PS), SS are prone to significant damage, necessitating a deeper understanding of their dynamic responses. The study introduces a novel modeling approach for analyzing the response of secondary structures (SS) under underground blast-induced ground motion (UBIGM). Utilizing MATLAB code for the Newmark’s Beta method, this research evaluates the peak acceleration of SS, considering variables such as mass ratio, explosive mass, and the transmission medium of the blast wave. The results reveal that peak accelerations of SS are 5.8 to 6.0 times higher when the blast waves travel through soil compared to rock, underscoring soil's amplifying effect on ground motion. Furthermore, linear regression analysis identifies the primary factors influencing SS response, leading to the development of a predictive equation for peak acceleration. These findings are instrumental in improving the design and survivability of SS against underground blast-induced excitations, thereby contributing to the overall safety and stability of structures in seismic-prone areas.