钢筋混凝土单层平面框架火灾行为的尺寸效应  

Size Effect on Fire Behavior of Reinforced Concrete Single-story Plane Frame

作　　者：张海燕[1] 李广洲 李绮玉 吴波[1] ZHANG Haiyan;LI Guangzhou;LI Qiyu;WU Bo(State Key Laboratory of Subtropical Building and Urban Science,South China University of Technology,Guangzhou 510640,China;College of Water Conservancy&Architectural Engineering,Shihezi University,Shihezi 832003,China)

机构地区：[1]华南理工大学亚热带建筑与城市科学全国重点实验室,广东广州510640 [2]石河子大学水利建筑工程学院,新疆石河子832003

出　　处：《湖南大学学报(自然科学版)》2025年第3期15-28,共14页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51978286);亚热带建筑与城市科学全国重点实验室自主课题(2022KB13)。

摘　　要：为探究钢筋混凝土框架结构火灾行为的尺寸效应,对6榀几何相似但比例不同的单层单跨钢筋混凝土平面框架结构开展标准升温条件下的明火试验,然后进行有限元模拟和参数分析,考察柱荷载比和梁荷载比对不同比例框架结构的破坏模式、变形发展以及耐火极限的影响.结果表明:相同受火条件下,几何尺寸和荷载水平相似的不同比例框架的耐火极限存在明显的尺寸效应,随试件尺寸增大,耐火极限增加,但增幅小于按文献中构件的耐火极限相似(或等效)关系推测出的增幅;火灾下钢筋混凝土平面框架结构的破坏模式受梁荷载比、柱荷载比的相对大小影响,当柱荷载比较小、梁荷载比较大时,易发生梁破坏,反之易发生柱破坏;由于混凝土柱的高温性能尺寸效应比混凝土梁的更显著,当小尺寸框架发生柱破坏时,几何和荷载水平相似的大尺寸框架可能发生梁破坏.To investigate the size effect on the fire behavior of reinforced concrete frame structures,fire tests on six single-story reinforced concrete plane frame structures with similar geometric characteristics but different scales were carried out under standard fire conditions.Then,finite element analysis and parametric studies were conducted to evaluate the effect of the column’s axial compression ratio and beam’s load ratio on the failure modes,deformation development,and fire resistance of the frame structures with different scales.The results show that there is a significant size effect on the fire resistance of geometrically similar frames under the same fire conditions and similar loading levels.The fire resistance increases as the sizes of the specimens increase,but the increasing extent is less than that predicted by the similarity(or equivalent)relationship of the fire resistance of the components proposed by previous studies.The failure mode of reinforced concrete plane frame structure under fire is greatly affected by the beam’s load ratio and the column’s axial compression ratio.When the column’s axial compression ratio is lower but the beam’s load ratio is higher,the frame structure is prone to beam failure,and otherwise it is prone to column failure.Due to the size effect on the columns being more significant than the size effect on the beams under fire,when column failure occurs in small-sized frames,beam failure may occur in large-sized frames with similar geometry and load levels.

关 键 词：钢筋混凝土框架 明火试验 有限元模拟 耐火极限 尺寸效应 

分 类 号：TU375[建筑科学—结构工程]