Effects of Blast Loading on Seismically Detailed Reinforced Concrete Columns

Terrorist attacks in recent decades have led to growing concerns about the performance of buildings designed by well-established conventional design methods under blast loading. The concerns arise from the response of buildings and fatalities in popular terrorist attacks such as the Alfred P. Murrah Building explosion. It has become imperative to investigate the performance of load-bearing members to blast loading. The effect of seismic detailing of RC columns on their blast-resistance was investigated using the LS-DYNA program. The blast resistance of the seismically-detailed columns increased, especially to close-in blast loading. The effects of axial load ratios (ALRs) were investigated in the numerical study. Increasing ALRs increased the blast-resistance of the columns. However, at high ALRs, the columns suffered compressive concrete crushing leading to higher lateral displacements and instability. At higher scaled distances, increasing ALRs resulted in reduced lateral displacements; with the seismically-detailed columns offering little advantage over the conventionally-detailed columns.