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Volume Title: ICASGE2023

DOI: ICASGE-STA

Zheng Dai; Li Shan ; Bo Yang

School of Civil Engineering, Chongqing University, Chongqing, China

This paper studies the progressive collapse robustness of a 10-story seismic designed composite building structure constructed by steel frames and steel-concrete composite floors, triggered by column removal scenarios including interior and perimetrical columns on each floor. The study aims at investigating the damage modes and stress redistribution in the process of the progressive collapse of of prototype structure. To consider building collapse induced by interstory impact, in which higher floors hit lower one and leads to chained collapse, a 3D macroscopic model of the structure is established using LS-DYNA. The FEM model adopted Hughes Liu Beam elements as columns and beams, integrated layered shell elements as composite floor slabs, and parrallel nonlinear springs as connections. To ensure its reliability for following simulations, the FEM model is validated by not only existing pushdown experiments of steel frame and composite floor subassemblies but also computational results of similar building suffered from column removal by previous researches. The results of a series of progressive collapse simulations for selected building reveal that the column removal on higher floors is prone to intensify progressive collapse compared to which on bottom floor, due to the Vierendeel action formed by higher stories. Additionally, removing the internal gravity column would aggravate progressive collapse in comparison with corner and perimetrical column. Lastly, composite floors contribute significantly to the integrity and progressive collapse robustness in contrast to merely-frame buildings, due to the membrane action of floor slabs.

Progressive collapse; Composite structure; FEM; Column removal; Membrane action

Structural Analysis (STA)