不同受火区域对多层钢框架结构抗连续倒塌机理研究  

Study on the mechanism of resistance to progressive collapse of multi-story steel frame structures in different fire areas

作　　者：李光涛 孙小博 邓炼 李治 Li Guangtao;Sun Xiaobo;Deng Lian;Li Zhi(College of Civil Engineering and Archiecture,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Green Building Materials and Construction Industrialization,Guilin 541004,China)

机构地区：[1]桂林理工大学土木建筑工程学院,广西桂林541004 [2]广西绿色建材与建筑工业化重点实验室,广西桂林541004

出　　处：《建筑科学》2023年第9期121-130,共10页Building Science

基　　金：广西科技基地和人才专项(2021AC19076);广西建筑新能源与节能重点实验室开发基金(桂科能22-J-21-5);广西中青年科研基础能力提升项目(2021KY0254)。

摘　　要：为探究不同受火区域工况对多层钢框架结构抗连续倒塌性能影响,对中柱失效的双层双跨钢框架梁-柱子结构进行Pushdown加载试验,研究其在倒塌过程中的抗力曲线和破坏模式.试验结果表明:中柱失效钢框架结构主要依靠弯曲机制和悬链线机制抵抗外加荷载,且悬链线机制具有一定的滞后性.随后通过有限元软件ABAQUS对钢框架结构进行数值模拟,对现实场景中可能出现的四种受火区域分别进行抗连续倒塌分析.有限元分析表明:受火工况均会导致结构极限承载力下降,全一层梁三面受火工况下极限承载力降低最大;全一层梁单面受火工况下极限承载力降低最小,结构抗力下降主要源于一层梁抗力衰减,一层梁受火对二层梁抗力机制的开展效果影响较小.In order to explore the influence of different fire region conditions on the resistance to progressive collapse of multi-story steel frame structure,Pushdown loading test is carried out on the double-deck double-span steel frame beam-column structure with middle column failure,and the resistance curve and failure mode in the process of collapse are studied.The test results show that the middle column failure steel frame structure mainly relies on the bending mechanism and the catenary mechanism to resist the external load,and the catenary mechanism has a certain lag.Then,the finite element software ABAQUS is used to simulate the steel frame structure,and the progressive collapse analysis is carried out on the four kinds of fire areas that may appear in the real scene.Finite element analysis shows that the fire conditions will lead to the decrease of the ultimate bearing capacity of the structure,and the ultimate bearing capacity of the whole layer of beam is the largest under the three-sided fire condition.The ultimate bearing capacity of the full-layer beam is reduced to the minimum under the condition of single-sided fire.The decrease in structural resistance is mainly due to the attenuation of the resistance of the first floor beam,while the fire on the first floor beam has a relatively small impact on the development of the resistance mechanism of the second floor beam.

关 键 词：钢框架结构 不同受火区域工况 Pushdown试验 有限元模拟 连续倒塌 

分 类 号：TU352.5[建筑科学—结构工程]