Structural response of a steel-frame building to horizontal and vertical travelling fires in multiple floors
File(s)1-s2.0-S037971121730139X-main.pdf (2.13 MB) 1-s2.0-S037971121730139X-main.pdf (2.49 MB)
Published version
Article In Press
Author(s)
Rackauskaite, E
Kotsovinos, P
Rein, G
Type
Journal Article
Abstract
During previous fire events such as the World Trade Centre Towers (WTC) 1, 2 & 7 in New York (2001), the Windsor Tower in Madrid (2005), and the Plasco building in Iran (2017), flames were observed to travel horizontally across the floor plate and vertically to different floors. Such fires are not considered as part of the traditional prescriptive structural design for fire. Recently, the Travelling Fires Methodology (TFM) has been developed to account for such horizontally travelling nature of fires. A dozen of studies have investigated the structural response of steel, concrete, and composite structures to a single-floor travelling fire. 5 out of 6 of the vertically travelling fire studies have been limited to the structures with a long span composite truss system as in the WTC Towers. The aim of this work is to investigate the response of a substantially different structural system, i.e. a generic multi-storey steel frame, subjected to travelling fires in multiple floors, and varying the number of fire floors, including horizontal and vertical fire spread. A two-dimensional 10-storey 5-bay steel frame is modelled in the finite element software LS-DYNA. The number of multiple fire floors is varied between 1 and 10, and for each of these scenarios, 5 different fire types are investigated. They include four travelling fire scenarios and the standard fire. In total, 51 fire simulations are considered. The development of deflections, axial forces, bending moments and frame utilization are analysed. Results show that the largest stresses develop in the fire floors adjacent to cool floors, and their behaviour is independent of the number of fire floors. Results indicate that both the fire type and the number of fire floors have a significant effect on the failure time (i.e. exceeded element load carrying capacity) and the type of collapse mechanism. In the cases with a low number of fire floors (1–3) failure is dominated by the loss of material strength, while in the cases with larger number of fire floors (5–10) failure is dominated by thermal expansion. Collapse is mainly initiated by the pull-in of external columns (1–3-floor fires; 1–9-floor fires for 2.5% TFM) or swaying of the frame to the side of fire origin (5–10-floor fires). This study has assessed a different structural form compared to previous literature under an extensive range of multiple floor travelling fire scenarios. We find that although vertically travelling fires result in larger beam axial forces and initial deflections, simultaneous travelling fires result in shorter failure times and represent a more onerous scenario for the steel frame investigated.
Date Issued
2017-04-28
Online Publication Date
2017-04-28
Date Acceptance
2017-04-11
ISSN
1873-7226
Publisher
Elsevier
Start Page
542
End Page
552
Journal / Book Title
Fire Safety Journal
Volume
91
Copyright Statement
© 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).
Source Database
manual-entry
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/K503381/1
n/a
Subjects
Science & Technology
Technology
Engineering, Civil
Materials Science, Multidisciplinary
Engineering
Materials Science
Modelling
Performance-based design
Structural response
Travelling fires
DESIGN METHODOLOGY
TALL BUILDINGS
COLLAPSE
0904 Chemical Engineering
Civil Engineering
Publication Status
Published