Effect of Soil Type on Failure of Steel Structures Under Blast Load, Considering Soil‐Structure Interaction

The dynamic response of a structure to destructive events, such as a blast, depends not only on the structural characteristics of the building but also on the properties of the surrounding soil medium. This study focuses on the effect of soil type on failure of steel structures due to an external blast, considering soil‐structure interaction. Therefore, 3‐story fixed base steel moment‐resisting frame structures were first modeled and subjected to an external blast load; after that, same structures were modeled with considering soil‐structure interaction by considering four different soil types. In addition, the impact of explosive charge on the occurrence of structural failures at a constant distance from the structures was examined, taking into account the soil‐structure interaction. The progressive collapse process of steel frames is simulated using both the direct simulation method and the alternative load path method within the commercial finite element program LS‐DYNA. The outcomes of the computational simulations revealed that the existence of soil‐structure interaction has a substantial impact on how the structure responds to a blast, and when the grain size of the assumed soil decreases, the structure exhibits a more critical behavior against blast.