摘要
高温后钢筋混凝土构件的剩余承载力会有所折减,利用ANSYS软件对火灾发生时钢筋混凝土梁内的最高温度分布进行分析,提出了计算高温后钢筋混凝土梁剩余承载力的数值方法,并通过具体算例来验证该方法的正确性,为高温后钢筋混凝土结构的安全评估及修复加固提供了理论依据.此外,还根据结构可靠度理论建立了高温后钢筋混凝土梁的抗力模型和极限状态方程,对影响抗力随机变量的统计参数给予分析,通过验算点法计算高温后钢筋混凝土梁在承受原设计荷载时可靠性指标的变化.分析表明,不同受火时间对梁的可靠性指标有很大的影响,在有条件下应给予考虑.
The load-carrying capacity of reinforced concrete （RC） beams is significantly reduced after exposure to high temperatures. ANSYS software was used to analyze heat distribution within a reinforced concrete beam in a fire. In addition, the force-resistance model and the limit-state equation of the beam after exposure to high tempera- ture was established. This allows statistical parameters of random variables that influence strength to be analyzed. Then the reliability indices of the beam under different temperature effects at the rated load were calculated using JCSS method. Based on this, a numerical method was developed to calculate the residual load-carrying： capacity of beams after exposure to high temperatures. A concrete example was used to test the feasibility of the proposed method, offering a theoretical basis for safety assessment and repair of reinforced concrete members after exposure to extreme heat. The results from the selected examples indicate that different fire durations have considerable impacts on the reliability of RC beams, which should be taken into account if possible.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2007年第10期1084-1088,共5页
Journal of Harbin Engineering University
基金
高等学校博士学科专项科研基金资助项目(20060217010)
关键词
高温
钢筋混凝土梁
剩余承载力
可靠性指标
high temperature
RC beam
residual load-carrying capacity
reliability index
