火灾降温阶段型钢混凝土框架结构受力性能研究  

Mechanical performance of steel reinforced concrete frame structures during fire including a cooling phase

作　　者：王广勇 刘人杰 郑蝉蝉 WANG Guangyong;LIU Renjie;ZHENG Chanchan(School of Civil Engineering,Yantai University,Yantai 264005,China;China Academy of Building Research,Beijing 100013,China)

机构地区：[1]烟台大学土木工程学院,山东烟台264005 [2]中国建筑科学研究院有限公司,北京100013

出　　处：《建筑结构学报》2022年第8期124-132,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51778595);烟台大学博士启动基金项目(TM20B73)。

摘　　要：在火灾降温阶段,结构构件的截面部分区域升温的同时,也有区域在降温,结构受力性能较为复杂,建筑结构更易发生倒塌破坏。为研究火灾降温阶段型钢混凝土框架结构的受力性能,通过已有火灾升降温条件下型钢混凝土框架及柱的受力性能试验,得到了构件截面的温度-时间关系曲线、结构变形-时间关系曲线,以及升降温过程中框架及柱的破坏形态。同时,采用有限元模型对升降温过程中型钢混凝土框架及柱的受力性能进行分析。结果表明:在火灾降温阶段,构件截面的升温区和降温区的范围在逐渐变化,截面的应力也随之发生变化。在此阶段,构件截面内部温度升高导致材料强度降低,截面外部处于降温区域的材料强度进一步降低,截面内外温差导致截面周围出现拉应力。上述因素的共同作用导致结构在火灾降温阶段发生破坏。相较于受火前,结构温度降至室温时结构的刚度降低、变形增加。In the cooling phase of a fire, there are temperature increase zone and decrease zone in a cross section of a structure member, which further deteriorates the performance of a structure. So, building structures are prone to collapse in the cooling phase of a fire. In order to study the mechanical performance of steel reinforced concrete(SRC) frame structures in the heating and cooling phases of a fire, the temperature-time curve, deformation-time curve, and collapse mode of the SRC frame structures during the fire including a cooling phase were obtained through experiments on the mechanical behavior of SRC frame structures from literatures. Base on the test data, a finite element analysis model was proposed to study the mechanical behavior of the SRC frame structures during the fire including a cooling phase. The results show that the temperature in the core of the cross section of the column is increasing while the temperature in the peripheral zone of the cross section is decreasing during the cooling phase of the fire, and the stress in the cross section changes with temperature. In the cooling phase, the strengths of concrete and steel in the temperature increase zone deteriorate, and those of the temperature decrease zone also deteriorate. The temperature difference in the column cross section can also induce tensile stress in the peripheral area of the cross section during the cooling phase of the fire. These factors mentioned above lead to the failure of the SRC frame structures in the cooling phase. The stiffness decreases and the deformation increases when the temperature of the SRC frame structures decreases to ambient temperature.

关 键 词：型钢混凝土框架 火灾 升温阶段 降温阶段 受力性能 

分 类 号：TU398.7[建筑科学—结构工程] TU311.41