Proposal on risk assessment of reinforced concrete structures subjected to explosive loads

Abstract

This study proposes an evaluation method to assess the risk of a reinforced concrete structure subjected to an explosive load such as that resulting from a terrorist bombing attack. First, a hazard curve that represents the relationship between the frequency of explosive incidents and the explosive mass was evaluated based on the statistics of terrorist bombing incidents. Second, to evaluate the damage state of the reinforced concrete structure due to the explosive load, fragility curves for the reinforced concrete members, such as beams, columns, and slabs, were evaluated using a single-degree-of-freedom model and a rotational capacity–based criterion. The fragility curve shows the relationship between the damage probability level, such as “no damage,” “small damage,” “collapse,” and an explosive mass. The total failure probability of the reinforced concrete structure was estimated by superposing the fragility curves of the members and by incorporating the reducing effect of floor slabs in the reinforced concrete structure on the blast load. A loss curve was drawn based on the damage state of the reinforced concrete structure by assuming the number of human lives lost and the reinforced concrete structure in each damage state. A risk curve was then derived by combining the hazard curve with the loss curve.