Simulation of blast-induced failure of case study structure

Abstract

This paper presents a study of the failure of column of Alfred Murrah Building due to an external explosion and assesses the partial progressive collapse of the front face of the building. The paper also looks at the general theory and behaviour of blast waves. A truck bomb of estimated 1800 kg TNT equivalent was exploded at the center, 4 m away from the column at G20. The failure of the column is simulated using finite element software Abaqus with the pressure load which is the equivalent blast load. It was found that the column failed due to tension. The study also shows the initiation and propagation of tension cracks using finite element. In addition, it shows the initiation and propagation of the tension cracks until the failure of the column. The progressive collapse is assessed by performing linear elastic static analysis without removing the structural column and after removing failed column G20. The results were used as per General Service Administration guidelines to check the failure of the other column and beams. The results show that the failure of G20 causes shear failure of columns at G16 and G24. This triggers the failure of the transfer girder at third floor of the structure which causes the progressive collapse of the front face of the building. The study compares the results obtained from simulations to the actual failure with the help of forensic pictures available.