火灾模型对钢交错桁架结构抗火分析的影响.pdf

中国工程热物理学会 燃烧学 学术会议论文 编号：084143 火灾模型对钢交错桁架结构抗火 分析的影响 陈长坤，张冬，肖荣 （中南大学防灾科学与安全技术研究所，长沙 410075） （Tel Email ：cckchen@ ） 摘要：采用合理的火灾作用模型是正确进行建筑结构防火分析的关键。对目前常用的四种火灾作用模 型进行了分析和总结，并以交错桁架这一新型高效的钢结构体系作为分析对象，运用这四种模型对该 体系的火灾热环境进行了模拟，研究不同火灾作用模型对其抗火分析的影响。研究表明：国际标准温 升曲线和参数化室内温升曲线缺乏针对性；区域模型所得温度偏低，但简单方便，可用于初步估算； 场模型考虑了火灾温度分布的不均匀性，和实际火灾较接近。 关键词：火灾模型；交错桁架；火灾响应；钢结构 Effect of Fire Models on the Analysis of Fire Resistance for Steel Staggered-Truss System CHEN Chang-kun, ZHANG Dong, XIAO Rong (Institute of Disaster Prevention Science Safety Technology, Central South University, Changsha, 410075) Abstract: Reasonable fire model is the linchpin of correct analysis on building fire-resistance. In this paper, the characteristics of four kinds of commonly used fire models are analyzed and summarized. The fire environment of steel staggered-truss, which is a new efficient construction system, is simulated by using these four models. The influence of different fire models on fire-resistance analysis of steel staggered-truss is studied. The result indicated that: ISO834 and parametric equation approach are lack of pertinence. The temperature obtained by zone model is low, but because of its simpleness and convenience, zone model can be used to estimate the fire-resistance behavior of structure preliminarily. Field model considers the heterogeneity of environmental temperature, and its result is more close to the real fire. Keywords: Fire Model; Staggered Truss; Fire Response; Steel Structure 0前言 钢结构对火灾热环境的响应主要包括两个方面：一个方面是钢构件材料的力学性能 和物理性能随温度升高产生的变化；另一个方面是由于构件热膨胀产生的附加内力导致 的整体结构的内力重分布[ 1-2] 。钢结构建筑的耐火极限与火灾时烟气的温升过程密切相 基金项目：国家自然科学基金资助项目） 关，而烟气的温升计算又取决于所采用