Evaluation of Response Spectrum for Models of Structures Against Blast Loading

The destruction as loss of life and prosperity occurs due to several types of blast explosives. Explosive upon explosion produces a huge amount of pressure and gases, which moves in all directions from the source point, cause damage to structures and the structure may collapse. Models of a few structures have been designed and analyzed to resist the physical and chemical explosives. The effect of the blast on structures also depends on the ductility ratio of structures. Study contains three types of structures, viz. reinforced—concrete frame structure, masonry structure, and reinforced—concrete frame structure with masonry infill, respectively. The structural properties of models are such as the height, width, size of the column, size of the beam of structural models are 3.2 m, 4.5 m, 500 mm × 500 mm, and 400 mm × 400 mm respectively. The thickness of masonry wall, grade of concrete, and grade of steel of structural models are 250 mm, M30, and Fe-415 HYSD steel, respectively. Analysis of the response spectrum has been done for structural models. The force–time—history is considered as a linear—equivalent triangle and a dynamic analysis has been performed. Calculation of blast load parameters has been done using IS: 4991-1968. The response spectrum of structures has been found from analysis with respect to the variation of structural stiffness for blast load of 20 kg explosive placed at a distance of 5 and 25 m. The study of response spectrum characteristics for models subjected to blast loads have been made with the variation of damping 0 and 5%.