Transient Effect of Blast Loads on RCC Building

Abstract

The increase in the number of terrorist attacks has shown that the effect of blast loading on structures is a serious matter that should be taken into consideration in the design process. The blast pressure on the structure due to nearby explosion is of very high magnitude and very short duration. Such an impulsive loading requires dynamic time-history analysis. This paper describes the nature of explosion of explosive materials and dynamic pressure developed on the nearby structure in lieu of explosion. Initially, efforts have been made to determine the effect of 1000 kg of C4 explosive material as an equivalent weight of TNT on different surfaces of a building model at a stand-off distance of 22.5m. The intensity of blast load on each surface is analytically determined as a record of pressure time history. Further attempts have been made to determine the effect of distance of blast for the same explosive material on building surfaces at stand-off distance of 10m, 18.5m, 22.5m and 27m. The effect of different explosives, i.e., TNT, C4, RDX and PETN on building surfaces at constant stand-off distance of 22.5m has also been determined. From the analysis, it is observed that the effect of blast load on front and rear surface of the building is critical. For close range explosions, deformations on front surface are more but with increase in stand-off distance, maximum deformations occur in roof surface.