Structural robustness analysis of RC frames under seismic and blast chained loads scenarios

In this paper the structural robustness assessment of concrete frame buildings under blast and under earthquake blast hazard chain scenarios is investigated. A deterministic methodology for connecting the robustness with the blast hazard intensity and for conducting the robustness analysis under earthquake-triggered blast is presented and applied to a 3D RC frame building by implementing nonlinear time history analyses considering both plastic behavior and large displacements. A preliminary sensitivity analysis on a 2D frame is conducted to identify the critical analysis parameters influencing the results. The robustness curves (residual structural capacity versus the level of damage occurring in the structure), evaluated both for the blast-only and for the earthquake-blast chained cases, are compared by considering different explosion locations inside the building (location of the blast-induced structural damage). Results show that neglecting the chained load scenarios would lead to the identification of an erroneous location as critical for the structural robustness performance.