相邻两面受火的内配型钢钢管混凝土柱的耐火极限

Fire-resisting limit of profile steel-encased steel tubular concrete column subjected to fire on its two adjacent surfaces

在实际工程中,由于柱子所处位置及墙体的吸热作用,柱子的受火边界发生改变,形成单面受火、相对或相邻两面受火和三面受火等非均匀的受火边界条件.基于ABAQUS有限元平台,计算内配型钢钢管混凝土柱在相邻两面受火条件下的耐火极限,剖析在受火过程中应力与应变的变化及发展情况,发现相邻两面受火时侧向挠曲变形有别于四面受火;最后,对影响耐火极限的主要因素进行参数分析.结果表明:火灾荷载比、长细比、荷载偏心率对耐火极限的影响较为显著,而钢管含钢率、型钢含钢率及保护层厚度对其影响不大.

In a practical engineering project, due to the different location of the column and the heat ab sorption function of the wall substance, the fire subjection boundary of the column will change, forming a fire subjection surface condition such as single sided, opposite or adjacent two sided, and three sided. Based on the finite element platform ABAQUS, the fire resisting limit of the profile steel encased steel tu bular column was calculated on the condition of its fire subjection on two adjacent side surfaces, the condi tion of variation and progression of the stress and strain in the column during fire subjection was analyzed, and it was found that its side flexural deformation was different from four surface fire subjection. Finally, parametric analysis of principal factor of influence on fire resisting limit was performed. The result shows that the fire load ratio, load eccentricity, and slenderness ratio of the column will have more remarkable effect on the fire resistant limit, but the influence of steel content ratio of steel tube and profile steel and protective layer thickness will be less.