首页|四周受火异形截面部分包覆钢-混凝土轴压组合柱耐火性能试验研究

四周受火异形截面部分包覆钢-混凝土轴压组合柱耐火性能试验研究

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  • 国家科技期刊平台
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异形截面部分包覆钢-混凝土组合(PEC)柱是解决高层钢结构住宅凸柱问题的有效方法之一,因其型钢翼缘外露,故而抗火问题备受关注.为研究异形截面PEC柱的抗火性能,以截面形式和轴压比为参数设计并制作了 4根异形截面PEC柱,开展了恒载升温试验,得到火灾下异形截面PEC柱的破坏模式、竖向与侧向变形-时间关系曲线和耐火极限,并分析其温度场分布与变形规律.研究结果表明:随着火灾下截面损伤增加,L形及T形截面PEC柱逐渐由轴压受力状态分别转为双向及单向偏压受力状态,十字形截面PEC柱仍保持轴压受力状态;在上端球铰和下端单向铰边界条件下,L形截面PEC柱发生双向弯曲失稳,T形截面PEC柱发生平面外弯曲失稳,十字形截面PEC柱发生平面内弯曲失稳;在轴压比为0.4、没有防火保护条件下,L形截面PEC柱耐火极限为41 min,T形截面和十字形截面PEC柱耐火极限分别为32.5 min和29 min;当轴压比由0.4增加至0.55时,十字形截面PEC柱耐火极限降低了 28.7％.借鉴EN 1994-1-2中建议的四周受火规则截面PEC柱高温承载力简化计算方法,对异形截面PEC柱高温承载力进行计算,计算结果偏保守.
Experimental study on fire resistance of axial-loaded special-shaped partially encased steel-concrete composite column subjected to fire on all sides
Special-shaped partially encased composite steel and concrete(PEC)columns is one of the effective solutions to solve the convex column problem of high-rise steel residential buildings.Due to the exposed steel flanges,its fire resistance has attracted much attention.In order to explore the fire resistance of special-shaped PEC columns,four special-shaped PEC columns were designed and fabricated with different cross-section shapes and axial compression ratios,and the fire tests with constant axial load were carried out.The failure mode,vertical and lateral deformation-time curves and fire resistance of special-shaped PEC columns under fire were obtained,and the temperature field distribution and deformation modes were analyzed.The results show that with the damage evolution under fire,L-shaped and T-shaped PEC columns gradually change from axial compression to bidirectional and unidirectional eccentric compression,respectively,while the cross-shaped PEC columns still maintain axial compression.Under the boundary conditions of the upper spherical hinge and the lower unidirectional hinge,the L-shaped PEC column fails in the bidirectional flexural buckling,the T-shaped PEC column fails in the out-of-plane flexural buckling,and the cross-shaped PEC column fails in the in-plane flexural buckling.Under the axial compression ratio of 0.4,the fire resistance of L-shaped PEC column without fire protection reaches 41 min,the fire resistances of T-shaped and cross-shaped PEC columns are 32.5 min and 29 min,respectively.When the axial compression ratio increases from 0.4 to 0.55,the fire resistance of the cross-shaped PEC column decreases by 28.7％.It is found that the simplified bearing capacity calculation method of regular cross-section PEC columns subjected to fire on all sides recommended in EN 1994-1-2 is conservative to predict the bearing capacity of special-shaped PEC columns at fire resistance.

partially encased composite steel and concrete columnspecial-shapedfire testfire resistancebearing capacity in fire

杨欢、刘用、王静峰、徐秋雨

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合肥工业大学 土木与水利工程学院,安徽合肥 230009

合肥工业大学 先进钢结构技术与产业化协同创新中心,安徽合肥 230009

合肥工业大学 土木工程结构与材料安徽省重点实验室,安徽合肥 230009

部分包覆钢-混凝土组合柱 异形截面 火灾试验 耐火性能 高温承载力

国家自然科学基金项目安徽省自然科学基金项目中央高校基本科研业务费专项资金中央高校基本科研业务费专项资金

521081302108085QE248JZ2021HGTA0158PA2021GDSK0078

2024

10.14006/j.jzjgxb.2022.0470

建筑结构学报
中国建筑学会

建筑结构学报

CSTPCD北大核心
影响因子：1.546
ISSN：1000-6869
年,卷(期)：2024.45(2)
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