圆形和方形截面钢管约束钢筋混凝土柱抗火性能对比分析  

Comparison on fire performance of circular and square steel tube confined reinforced concrete columns

作　　者：杨冬冬 刘发起[1,2] 杨华[1,2] YANG Dongdong;LIU Faqi;YANG Hua(Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin 150090,China;Key Lab Of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨150090 [2]哈尔滨工业大学土木工程智能防灾减灾工业和信息化部重点实验室,黑龙江哈尔滨150090

出　　处：《建筑结构学报》2018年第11期65-73,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51508131);中国博士后科学基金项目(2016M591535)

摘　　要：为研究圆钢管与方钢管约束钢筋混凝土柱火灾下力学性能的差异,采用ABAQUS软件建立圆形和方形截面钢管约束钢筋混凝土柱温度场和耐火极限的有限元分析模型,以截面尺寸、荷载比和长细比等为参数,分析了截面温度的分布规律以及不同参数对耐火极限的影响,比较了圆钢管和方钢管约束钢筋混凝土柱抗火性能的差异。研究结果表明：相同截面形状系数（单位长度构件外表面直接受热面积与其体积的比值）下,方钢管与圆钢管约束钢筋混凝土柱的截面温度分布规律类似,方形截面内部混凝土的温度较圆形截面相同位置处的略低,前者的耐火极限高于后者,且构件长细比与荷载比越小,二者耐火极限差距越显著;当长细比为30时,对于荷载比不超过0.5且截面边长不小于600 mm的方钢管约束钢筋混凝土柱,其耐火极限可达到或超过柱类构件一级耐火极限3 h的要求,而对于圆钢管约束钢筋混凝土柱,仅当荷载比更小且截面直径更大时,才能满足这一要求。In order to investigate the differences in the fire performance between circular and square steel tube confined reinforced concrete （STCRC） columns, a finite element model was developed using the program ABAQUS. Heat transfer analysis and stress analysis were carried out, where the examined parameters included cross-section dimension, load ratio and slenderness ratio. The temperature distributions of the composite cross-section and the effects of various factors on the fire resistance were analyzed and the differences in the fire performance between circular and square columns were discussed. While the temperature of the circular section is slightly higher than that of the square one with the same section factor, the temperature distributions of these two sections are similar. The fire resistance of the square STCRC columns is much higher than that of the circular ones, especially for the columns with lower slenderness ratios and load ratios. With a slenderness ratio of 30, the fire resistance of the square STCRC columns can exceed 3 h when the load ratio is lower than 0.5 and sectional dimension is larger than 600 mm. However, this limit can only be reached for circular columns with much lower load ratios and larger diameters.

关 键 词：钢管约束钢筋混凝土柱 方形截面 圆形截面 有限元分析 温度场 耐火极限 

分 类 号：TU398.902[建筑科学—结构工程] TU311.41