考虑火灾全过程的空间双向张弦梁结构倒塌分析  

Collapse analysis of spatial two-way beam string structure considering the whole process of fire

作　　者：殷志祥[1] 王孟玉 YIN Zhi-xiang;WANG Meng-yu(School of Civil Engineering,Liaoning Technical University,Fuxin 123000,China;The 5th Engineering Co.,LTD of China Railway 18th Bureau Group Co.,LTD,Tianjin 300450,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]中铁十八局集团公司第五工程有限公司,天津300450

出　　处：《空间结构》2021年第3期25-31,共7页Spatial Structures

摘　　要：火灾下张弦梁结构的倒塌分析不同于爆炸、撞击等偶然荷载下的结构倒塌分析,火灾作用时间长且影响范围广,因此火灾下张弦梁结构的倒塌分析中不能单纯关注局部关键构件的破坏.基于此,提出了兼顾火灾全过程及结构整体响应的全过程分析法.在此基础上,采用有限元分析软件ANSYS建立某双向张弦梁整体传热模型及外荷载和温度荷载共同作用的受力模型,对双向张弦梁结构的火灾全过程进行模拟分析,给出两种功率火灾下双向张弦梁结构的内力与火灾持续时间的关系曲线,得到大功率火灾下双向张弦梁失效构件位置、结构失效时间及张弦梁结构的倒塌过程.最后给出提升火灾下双向张弦梁结构抗倒塌性能的改进方法,并对3种改进后的张弦梁结构在相同荷载条件下的倒塌过程进行模拟分析.结果表明,合理增设辅助撑杆可以有效改善火灾下张弦梁结构抗连续倒塌性能,并从破坏时间及破坏时结构最大挠度两方面考虑来选出最优方案.The collapse analysis of beam string structure under fire is different from which is under accidental load such as explosion, impact and so on. The fire action time is long and the influence range is wide. Therefore, the collapse analysis of beam string structure under fire cannot only focus on the failure of local key components. Instead, the whole process analysis considering the whole fire process and the overall response of the structure is preferred and put forward. On that basis, the whole heat transfer model of a two-way beam string structure and the analysis model of the interaction of external load and temperature load are established by using the finite element analysis software ANSYS. The whole process of the two-way beam string structure subjected to fire is simulated and analyzed. The relationship between the internal force of the structure and the fire duration under two kinds of power fire is obtained, and the position of the failure component, the failure time of the structure and the collapse process of the beam string structures under high power fire are obtained. Finally, the improved method of anti-collapse performance of two-way beam string structure under fire is given, and the collapse process of three kinds of improved beam string structures under the same load is simulated and analyzed. Results show that the reasonable arrangement of supplementary strut can effectively improve the anti-progressive collapse performance of beam string structure under fire, and the optimal scheme can be selected from two aspects of failure time and maximum deflection of the structure.

关 键 词：双向张弦梁 火灾 全过程分析 结构倒塌 辅助撑杆 

分 类 号：TU393.3[建筑科学—结构工程]