Probability Assessment and Risk Management of Progressive Collapse in Strategic Buildings Facing Blast Loads

Nowadays, as a result of increased terrorist and bomb attacks throughout the globe in the vicinity of strategic buildings, designing these structures against impact loads, particularly the blast-related ones, has been taken into more consideration. The current procedure for designing the structure against an explosion is a design against the local failure of the current elements in the first step and then, in the next step, against local damage as well as tactful thinking to prevent this damage from spreading to other parts of the structure. The present research investigates the impacts of explosives, derived from probable terror–stricken scenarios inside and outside a strategic four-story steel building with a special moment frame system. Then, the resistive capacity of the damaged building (due to blast) has been evaluated against the progressive collapse, and finally, the rate of the collapse risk and the reliability of the structure have been obtained by presenting a probable method. Thus, the vulnerable parts inside and outside the building are identified and safety measures have been determined, so that in case of no safety or excessive collapse risk- access to dangerous parts of the building could be reinforced or limited. Results show that progressive collapse probability and reliability of the building are 57% and 43% respectively.