Performance of steel moment‐resisting beam‐supporting column transfer structures under fire

Abstract

Summary This paper investigates the structural fire response of steel beam‐supporting column transfer structures. Two three‐story (Case 1) and seven‐story (Case 2) structures with different span lengths are designed first to withstand gravity and seismic loads. All the structural members are also designed to meet their required fire resistance ratings based on the ISO834 fire. The structural vulnerability is then evaluated under two fire scenarios: the natural fire as a uniform and the traveling fire as a nonuniform temperature distribution inside the structures. The fire loads are applied to the first story of the structures where the structural irregularity is evident. The natural fires are determined based on Eurocode 1 and based on different opening ratios of 0.04, 0.067, 0.08, 0.12, and 0.16 to provide different duration of the heating phase. The results indicate that under the uniform fire scenarios, Case 1 collapses after 134 min under the opening ratio of 0.04. As well, Case 2 collapses under the opening ratios of 0.04, 0.67, and 0.08 at 95, 142, and 160 min, respectively. The results also show that under the nonuniform fire with a size of 25%; Case 1 collapses at 89 min, and Case 2 collapses at 93 min. Although it is believed that the cases studied should logically remain stable under possible fire scenario, the results indicate that this is not a true presumption. The results of this study provide beneficial information about structural fire response of beam‐supporting column transfer structures as an important structural irregularity.

Flexural design curves of steel plate I‐girders at elevated temperatures: I‐girders with yield or local buckling failure mode

“…Reviewing the prior art shows that significant researches have been done in the field of flexural performance of hot‐rolled beams prone to local buckling and LTB at ambient temperature. At elevated temperatures, most of the numerical and experimental studies have been allocated to formulate the flexural behavior and effective factors of columns and hot‐rolled beams, most of which address the LTB failure mode of the beams 33–41 . Meanwhile, the research for steel plate girders, which are mainly composed of slender sections, is not adequate 22 .…”

“…At elevated temperatures, most of the numerical and experimental studies have been allocated to formulate the flexural behavior and effective factors of columns and hot-rolled beams, most of which address the LTB failure mode of the beams. [33][34][35][36][37][38][39][40][41] Meanwhile, the research for steel plate girders, which are mainly composed of slender sections, is not adequate. 22 As a result, the lack of experimental and numerical data in this field led to the fact that the existing flexural design provisions do not provide acceptable outcomes for slender sections at elevated temperatures.…”