PROPOSAL OF AN EVALUATION METHOD FOR FLEXURAL RESPONSE OF RC BEAMS SUBJECTED TO DISTRIBUTED LOAD CAUSED BY CLOSE-IN EXPLOSION

Abstract

 This study proposes a failure mechanism and a method for evaluating the flexural response of RC beams subjected to close-in explosion to develop a safety assessment method and protective design of structure subjected to explosive loads. First, to examine the spatial distributions, explosion tests were conducted with C-4 explosives. Approximation formulae for the spatial distributions of the peak over-pressure and impulse were proposed by using the variables of explosive mass, stand-off distance, and target member length. Secondly, close-in explosion tests on RC beams using C-4 explosives were conducted. The measurement parameters were pressure acting on the beam, maximum and residual displacements at the center of the beam, strain of the lower longitudinal reinforcing bar, and reaction force. The failure mechanism of RC beams subjected to close-in explosion was examined. Finally, the method for evaluating the flexural response of RC beams considering the blast load distribution owing to close-in explosion was proposed.