Effect of Dynamic Material Strength on Blast Response of Earthquake-Resistant RC Buildings

This study examines the influence of dynamic material strength on the blast response of reinforced concrete (RC) buildings. The structural response of four RC buildings, designed to resist various seismic demands with three different infill strengths, is examined under surface burst using an uncoupled approach. The time-histories of blast-induced loads are imposed directly on the beam-column joints that are exposed. Nonlinear dynamic response history analysis is then performed to acquire different responses. It is observed that the consideration of dynamic material strength results in around a 5.0% reduction in the peak displacement at different floor levels. Nevertheless, the variation of the peak displacement with floor level and with respect to scaled distance (\(Z),\) as well as the variation of peak interstory drift ratio (IDR) with \(Z\) are similar to that of buildings without considering dynamic material strength. In addition, the effect of infill strength is found to be insignificant on this response reduction. Further, the response reduction due to dynamic material strength is found to be less in buildings designed for lower seismic demand in comparison to those designed for higher seismic demand. Furthermore, probabilistic assessment demonstrated that accounting for uncertainty in blast load parameters such as charge weight and standoff distance plays a significant role in the accurate assessment of blast response as it results in the increase of peak IDR response in buildings with lesser infill strength and lower seismic demands.