钢框架关键构件在火灾环境下安全评价方法

The Key Component Steel Frame under the Environment of Fire Safety Assessment Program

以构件强度和变形限制来判断是否需要加固,达到既不盲目加固又能保障安全的目的。根据钢结构和火灾学理论,采用火灾环境下钢框架关键构件为研究对象,选取火灾荷载密度、火灾持续时间和火灾温度为安全评定主要参数,根据构件的平均应力比来定义该温度工况下的关键构件,运用有限元对一个四层三跨钢框架进行热力耦合分析,提出了钢框架关键构件在火灾环境下的安全评价程序。以一个四层三跨受火钢框架为例,火灾环境下的关键构件承载力已经达到极限状态,不能满足承载力设计要求,需进行结构防火加固或构件替换。此方法可为钢结构建筑火灾安全鉴定及加固提供借鉴参考。

The component strength and deformation limit are used to determine whether there is need to strengthen in order to achieve the goal of strengthening the security without blind reinforcement. According to the theory of steel structure and fire science, using key component of steel frame under the environment of fire as re- search object, selecting fire load density, duration of fire and fire temperature as main parameters of safety as- sessment, the key component of the temperature condition is defined according to the average stress ratio of the component. Using the finite element analysis of thermo mechanical coupling for a three span four storey steel frame and a safety assessment program for key components of steel frame under the environment of fire put for- ward. The research shows that the bearing capacity of the key components under the environment of fire reaches the limit state, which can not meet the design requirements of bearing capacity. This method can be used for ref- erence for the fire safety appraisal and strengthening of the steel structure building.