Progressive Collapse of Steel Structures Under Blast Loads Considering Soil-Structure Interaction

This study focuses on the effect of soil-structure interaction on the occurrence of progressive collapse due to an external blast. Therefore, a 3-story fixed base steel moment-resisting frame structure was first modeled and subjected to an external blast load. Then, the same structure was modeled considering soil-structure interaction. In another stage of this study, the effect of plan irregularity on progressive failure resulting from the explosion was investigated, assuming the presence or absence of soil-structure interaction. The direct simulation method and alternative load path method are all employed to simulate the progressive collapse process of steel frames using the commercial finite element program LS-DYNA. The results of the numerical simulations demonstrated that the presence of soil-structure interaction, significantly influences the response of the structure to the blast and this interaction increases the likelihood of progressive failure occurring even at symmetric and asymmetric structures. It was also shown that silty sand soil yields more critical conditions than other types of soil in the event of failure after the occurrence of an explosion in the structure.