Passive Defense Necessities in Design of Concrete Staircases

One of the most important parts in densely populated places is staircases that cause irreparable damage if they are ignored. A staircase is a place for entrance and exit. In crisis time, it is a way for running and assistance. Therefore; paying careful attention to the design of staircases can reduce any possible damage. In this article, the necessities of passive in the design of staircases have been presented which is intended to take the design regulations to deal with crisis and consequently to reduce fatalities and collateral damage. This article initially introduces the load members of a concrete staircase. Then, in an explosion analysis using the ABAQUS finite element model, the layout and adequacy of bearing members has been evaluated. The assumptions in this research are made based on external type explosion and moreover, the staircase has been analyzed independent of the structure against blast load. The effects of surrounding walls of the staircase box has been neglected because of low resistance against explosion loading. The results show that the minimum damage will be obtained if the staircase is located at center of building. In addition, increasing the thickness of concrete slab in connection with zone between ramp slab and landing slab can reduce deflection of staircase.