Reliability of Steel Building Subjected to Blast Loading

Abstract

In recent years, explosive devices are the weapon of choices for the majority of terrorist attack that not only affect the life of human beings but also the structural resistance and physical integrity. Bomb explosion near the building can cause such an amount of pressure and produce a large amount of heat resulting a high strain loading on building and its elements. Such a high strain loading can cause catastrophic damage to the building’s external and internal structural frames, collapsing of walls, blowing out large expanse of windows and shutting down of critical life safety systems. Due to such impact of this large dynamic loading, efforts have been made during the past few decades to develop methods of structural analysis and design of blast resistance structure. Since blast resistant design is the important topic of study and therefore requires the careful understanding about the blast phenomena and its effect and impact on various structural elements. In the present study, the response of steel frame building subjected to blast loading, for different standoff distances has been examined by calculating blast load manually using an empirical procedure established in the literature and applying on joints as a time history loading. The different statistical properties, like normal distribution, arithmetic mean, standard deviation, skewness and kurtosis of the charge weight and the output quantities have been studied and compared from the results obtained. The probability of failure for different values of charge weight has been computed by running the Monte Carlo Simulations. The fragility curves for the two faces of the building have been plotted for different standoff distances. It has been observed that probability of failure was lower when the blast occurs opposite the face containing column flanges than the other face. Based upon the results interpretation, it is recommended that the parking lots should not be constructed in front of the face of the building and a minimum distance from the face of the building should be kept 10 m and these should always be constructed around the corners, such that the angle of incidence of the blast load to the main structural frame of the building always remain at higher values, since this reduces the blast load significantly.