Response Behavior of Buildings under the Simultaneous Actions of Surface Blast and Progressive Collapse

Due to the near blast condition, columns on the front face of the building may snap off in the blast load's initial state, leading to a condition of the blast load and progressive collapse effects occurring simultaneously. Herein, the damages caused in the building produced due to progressive collapse under blast loading scenario are investigated. A nonlinear time history analysis of the three-dimensional (3D) model of a six-story building is performed for the progressive collapse following General Services Administration (GSA) guidelines. The surface blast effect is included using simulated air pressure and ground motion produced due to the blast. The progressive collapse analysis is performed for two cases, namely, (1) considering blast effect due to surface blast; and (2) neglecting the effects of the blast wave, and the results of the two cases are compared. The study results show that the effect of the duration of the transient loading used for the progressive collapse analysis has a significant influence on the response quantities of interest. Further, all response quantities of interest are considerably increased when the blast effect is considered compared to the case when the same is neglected.