Affiliation:
1. School of Civil Engineering and Architecture, University of Jinan, Jinan 250024, China
2. School of Civil Engineering, Shandong Jianzhu University, Jinan 250101, China
Abstract
Steel columns, which are widely used in building frameworks and spatial structures, are susceptible to capacity degradation during fires, potentially leading to the overall collapse of buildings. Existing research on the fire resistance of steel columns assumes that the temperature loads encountered by steel columns are evenly distributed vertically. However, real-world fire scenarios often feature significant vertical temperature differences. Therefore, this study comprehensively investigated these variations to derive a temperature curve that accurately represents real fire conditions. Subsequently, the fire resistance limits of steel columns were studied using this temperature curve, leading to a revised calculation formula for the critical fire resistance temperatures of steel columns. The following conclusions were drawn: (1) Nonuniform longitudinal temperature distributions are influenced by parameters such as the fire source distance, the heights of ventilation openings, and the distance between a vent and the temperature measurement point. Among them, the fire source distance has the greatest impact, with the maximum longitudinal temperature difference reaching over 500 °C. (2) Variations in the load ratio and longitudinal temperature differences alter the failure positions of steel columns, reducing their critical temperatures by up to 200 °C. (3) The revised critical fire resistance temperature formula is more accurate and safer compared with that outlined in the “Technical Code for Fire Protection of Steel Structures” (GB51249-2017). These findings offer valuable insights for the fire designs of steel columns.
Funder
National Natural Science Foundation of China
Reference31 articles.
1. (2002). Actions on Structures–Part 1–2: General Actions–Actions on Structures Exposed to Fire (Standard No. EN 1991-1-2).
2. Aasen, B. (1985). An Experimental Study on Steel Column Behaviour at Elevated Temperatures, Institutt for Stålkonstruksjoner, Universitetet i Trondheim, Norges Tekniske.
3. The effect of axial restraint on the fire resistance of steel columns;Ali;J. Constr. Steel Res.,1998
4. Stability of axially restrained steel columns under temperature action;Cai;Sci. China Technol. Sci.,2010
5. Mechanical properties of heat-treated high strength steel under fire/post-fire conditions;Chiew;J. Constr. Steel Res.,2014