Pre- and Post-earthquake Fire Response of Partitioned Steel Structures: A Performance-based Approach

نوع مقاله : مقاله پژوهشی

نویسنده

School of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran

چکیده

In addition to the damage caused by the earthquake itself, post-earthquake fires (PEF) can potentially create even more significant damage than the earthquake itself. Therefore, in the absence of established provisions for PEF, a series of investigations need to be performed in order to develop a better understanding of the issue. As these investigations should be in the direction of performance-based approach, where providing adequate safety for the buildings’ inhabitants is aimed, compatible methods should thus be employed to simulate the issue. A sequential structural analysis is performed here on the Life Safety performance level of a five story steel moment resisting frame. The frame is first subjected to an earthquake load with the PGA of 0.35g. This is followed by a fire analysis, using the ISO834 fire curve and the iBMB fire curve. The time it takes for the structure weakened by the earthquake to collapse under fire is then calculated. As a point of reference, fire-only analyses are also performed for undamaged frame. The results show that while the fire resistance of the frame exposed to ISO curve and iBMB curve are almost similar to each other (about 27 minutes), the failure shape are completely different. By contrast, while the PEF resistance of the frame exposed to ISO curve is around 26 minutes, it is less than 17 minutes under iBMB curve. Nevertheless, the failure shapes in case of PEF analysis and under both curves are almost the same. It is then concluded that the fire and PEF analysis under iBMB curves are more compatible with the concept of performance-based design. Whilst the investigation is for a certain class of buildings, the results confirm the need for the incorporation of PEF in the process of analysis and design, and provide some quantitative measures on the level of associated effects.

کلیدواژه‌ها


عنوان مقاله [English]

Pre- and Post-earthquake Fire Response of Partitioned Steel Structures: A Performance-based Approach

نویسنده [English]

  • Behrouz Behnam
School of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran
چکیده [English]

In addition to the damage caused by the earthquake itself, post-earthquake fires (PEF) can potentially create even more significant damage than the earthquake itself. Therefore, in the absence of established provisions for PEF, a series of investigations need to be performed in order to develop a better understanding of the issue. As these investigations should be in the direction of performance-based approach, where providing adequate safety for the buildings’ inhabitants is aimed, compatible methods should thus be employed to simulate the issue. A sequential structural analysis is performed here on the Life Safety performance level of a five story steel moment resisting frame. The frame is first subjected to an earthquake load with the PGA of 0.35g. This is followed by a fire analysis, using the ISO834 fire curve and the iBMB fire curve. The time it takes for the structure weakened by the earthquake to collapse under fire is then calculated. As a point of reference, fire-only analyses are also performed for undamaged frame. The results show that while the fire resistance of the frame exposed to ISO curve and iBMB curve are almost similar to each other (about 27 minutes), the failure shape are completely different. By contrast, while the PEF resistance of the frame exposed to ISO curve is around 26 minutes, it is less than 17 minutes under iBMB curve. Nevertheless, the failure shapes in case of PEF analysis and under both curves are almost the same. It is then concluded that the fire and PEF analysis under iBMB curves are more compatible with the concept of performance-based design. Whilst the investigation is for a certain class of buildings, the results confirm the need for the incorporation of PEF in the process of analysis and design, and provide some quantitative measures on the level of associated effects.

کلیدواژه‌ها [English]

  • Post earthquake fire
  • Fire resistance
  • Steel structures
  • Performance Based Design
  • iBMB fire curve