Steel Framed Structures Subjected to the Combined Effects of Blast and Fire - Part 1: State-of-the-Art Review

Abstract

Design of public infrastructure against terrorism has become a rising concern with the objective of reducing the level of damage to property and the loss of life. Some of the terrorism acts take the form of blast followed by fire causing catastrophic failure of the structure. This paper studies the response of steel framed structures subjected to the combined effects of blast and fire. A state-of-the-art summary on issues related to separate assessment of blast and fire resistance of multistory building frames is provided. This is followed by a systematic investigation on the combined effects of blast and fire using a proposed two-step dynamic analysis procedure. In Part 2 of a companion paper, a typical multi-storey building will be analyzed to study its behavior under a medium-scale explosion which triggers a post-blast fire in the affected compartment. This particular structure is found to be vulnerable as it possesses little fire resistance due to the high level of deformation caused by the blast load. The aim of this two-part paper is to advance the use of simulation tools for c co ol ll la ap ps se e a an na al ly ys si is s o of f three dimensional steel structures s su ub bj je ec ct t t to o a at tt ta ac ck k b by y f fi ir re e a an nd d e ex xp pl lo os si io on n so that the complex interaction effects of blast and fire can be understood and quantified.

Effect of Blast-Induced Column Failure Pattern on Collapse Behavior of Steel Frames

“…Comparison of the mid-span lateral displacement of the damaged column between the frame model and SDOF model is shown in Figure 7. The parameters for the equivalent SDOF model were taken as K=2.31×10 6 kN/m，M=202kg，P=28.8×10 6 kN，R=7.82×10 6 kN. The maximum displacement and failure time of the column in the SDOF model agreed well with those from the frame model.…”

“…Liew and Chen [4,5] studied the behavior of steel columns under various blast loads and boundary conditions. Yu and Liew [6,7] investigated the behavior of steel framed structures subjected to combined blast and fire loads. The methods for determining the blast load and finite element techniques were reviewed, and numerical analysis of a five-storey building under blast and fire conditions were carried out.…”

Analysis on the Dynamic Responses of Steel Beam under the Condition of Heat and Blast Loads

“…The response behaviors of steel structures under both the blast and fire loading were studied, and the influence of blast loading on the fire resistance capability of multistory steel frames was elaborated. Yu and Liew [15][16] analyzed the situation that frame structure was impacted by explosive load and cause a fire.…”

Experimental behaviour of a thermally restrained plate girder loaded in shear at elevated temperature

“…Although these tests provided valuable information on behaviour of steel beam web panel under shear at high temperatures, there is still a lack of investigations about non-isolated behaviour of steel beams in the integrated steel structures. For steel-framed buildings subjected to fires or combination of blast and fire, thermal expansions of steel beams were normally restrained laterally by carried concrete slabs and axially restrained by adjacent cool structures [8][9][10], however, in which axial restraint played a important role influenced the mechanical behaviour of steel beams at elevated temperatures [11,12]. In these restrained beam tests conducted at elevated temperatures [11,12], significant axial forces have been measured in the heated beams due to column restraints.…”

“…Despite the complicated behaviour of steel beams in fire, this project was set up firstly to investigate the effects of axial restraints on steel plate girder beams in fire, especially focused on influences from thermal restraint on beam web shear behaviour. During the past decade, research works intensified on the behaviour of individual members and steel structures in fire conditions [13,8,9] gained momentum. On member behaviour, a number of experimental and analytical studies on steel beams and columns under elevated temperature conditions have been conducted, such as, [11,[14][15][16].…”