火灾下混凝土框架结构力学性能研究  

Study on Mechanical Properties of Concrete Frame Structure under Fire

作　　者：宋岩升[1] 潘勇旭 赵刚 SONG Yansheng;PAN Yongxu;ZHAO Gang(School of Civil Engineering,Shenyang Jianzhu University,Shenyang,China,110168)

机构地区：[1]沈阳建筑大学土木工程学院,辽宁沈阳110168

出　　处：《沈阳建筑大学学报（自然科学版）》2021年第1期77-85,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：“十三五”国家重点研发计划子课题(2018YFC1504303-05);辽宁省教育厅科学研究项目(lnjc201906)。

摘　　要：目的模拟高层混凝土框架结构的火灾全过程并研究火灾后框架结构及构件力学性能,为此类结构火灾后的损伤评估与加固方案设计提供参考依据。方法利用火灾模拟软件PyroSim对某高层宿舍楼首层火灾进行模拟,研究室内火灾下温度场分布,应用ABAQUS有限元软件分析火灾下结构和构件的温度场,以及静、动力作用下结构和构件的变形及内力。结果通风条件对室内火灾温度场影响较大,实际升温曲线与ISO834标准升温曲线结果存在一定差异;梁、柱构件截面温度场分布不均匀,绝大部分面积温度未超过500℃,节点核心区的温度较周围的梁段和柱段偏低,受火后梁CD、柱C和柱D最大极限承载力剩余约为35.4%、26.4%和62.7%,结构尚余部分承载力仍可继续使用;受火后框架首层在地震作用下层间位移角明显增大,2~8层增幅逐渐递减,首层结构在EI-Centro波、唐山波作用下层间位移角超出规范限值约16.5%、48.9%。结论建议用PyroSim火灾模拟软件得到的升温曲线进行结构分析;火灾后应重点检测过火区域构件力学性能,计算首层层间位移角变化,据此制定加固方案。Simulate the entire fire process of a high-rise concrete frame structure and study the mechanical properties of the frame structure and components after the fire,and provide a reference for the damage assessment and reinforcement scheme design of such structures after a fire.Use the fire simulation software PyroSim to analyze the first-floor fire of a high-rise dormitory building perform simulations to study the temperature field distribution under indoor fire,and use ABAQUS finite element software to analyze the temperature field of structures and components under fire,as well as the deformation and internal forces of structures and components under static and dynamic actions.Ventilation conditions have a greater impact on the indoor fire temperature field.The actual heating curve is different from the ISO834 standard heating curve;the temperature field distribution of beam and column members is uneven,and the temperature of most areas does not exceed 500℃.The temperature of the core area of the node is lower than that of the surrounding beam and column sections.After the fire,the remaining maximum ultimate bearing capacity of beam CD,column C and column D is about 35.4%,26.4%and 62.7%.The remaining part of the bearing capacity of the structure can still be used;the displacement angle of the first story of the frame after the fire is affected by the earthquake significant increase,the increase of 2~8 floors gradually decreases.Under the action of EI-Centro wave and Tangshan wave,the displacement angle between floors of the first floor structure exceeds the specification limit by about 16.5%and 48.9%.It is recommended to use the heating curve obtained by PyroSim fire simulation software.Carry out structural analysis;after the fire,the mechanical properties of the components in the fired area should be inspected,and the displacement angle changes between the first floors should be calculated,and the reinforcement plan should be formulated accordingly.

关 键 词：混凝土框架 火灾模拟 有限元分析 升温曲线 高层建筑 

分 类 号：TU391[建筑科学—结构工程]