In this paper, we review the state-of-the-art experimental research on large open-plan compartment fires from the past three decades. This will allow for knowledge-driven, quantifiable factors of safety to be used in the design of highly optimised modern tall buildings. Therefore, an accurate representation of the design fire for open-plan compartments is required for the purposes of design. With the continued increase in height and complexity of tall buildings, the risk to the occupants from fire-induced structural collapse increases, thus understanding the performance of complex structural systems under fire exposure is imperative. Numerous high-profile fire-induced failures have highlighted the inadequacy of existing tools and standards for fire engineering when applied to highly-optimised modern tall buildings. This study contributes to the creation of design tools for better structural fire engineering.ĭevelopments in the understanding of fire behaviour for large open-plan spaces typical of tall buildings have been greatly outpaced by the rate at which these buildings are being constructed and their characteristics changed. These findings mitigate the uncertainty around the TFM near field model and confirm that it is conservative for calculation of the thermal load on structures. The results show that for all cases, TFM results in higher structural temperatures compared with different fTFM models (600☌ for concrete rebar and 800☌ for protected steel beam), except for the Wakamatsu model that for small fires, leads to approximately 20% higher temperatures than TFM. The peak heat flux is from 112 to 236 kW/m2 for the majority of fire sizes using the Wakamatsu model and from 80 to 120 kW/m2 for the Hasemi and Lattimer models, compared with 215 to 228 kW/m2 for TFM. The duration of the exposure to peak heat flux depends on the flame length, which is 53 min for fTFM compared with 17 min for TFM, in the case of a slow 5% floor area fire. The near field length with flame extension (fTFM) is found to be between 1.5 and 6.5 times longer than without flame extension. The methodology is applied to an open‐plan generic office compartment with a floor area of 960 m2 and 3.60 m high with concrete and with protected and unprotected steel structural members. The Hasemi, Wakamatsu, and Lattimer models of heat flux from flame are investigated for the near field. It also formulates the thermal boundary condition in terms of heat flux rather than in terms of temperature as it is used in TFM, which allows for a more formal treatment of heat transfer. This paper revisits the near field assumptions of the TFM and, for the first time, includes horizontal flame extension under the ceiling, which affects the heating exposure of the structural members thus their load‐bearing capacity. TFM assumes a near field temperature of 1200☌, where the flame is impinging on the ceiling without any extension and gives the temperature of the hot gases in the far field from Alpert correlations. The travelling fire methodology (TFM) defines the thermal boundary condition for structural design of large compartments of fires that do not flashover, considering near field and far field regions. Structures need to be designed to maintain their stability in the event of a fire.
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