建筑结构学报2025，Vol.46Issue(3)：153-163,11.DOI:10.14006/j.jzjgxb.2024.0210
既有桁架屋盖建筑火致倒塌试验与数值模拟
Experimental and numerical study on fire-induced collapse of an existing truss roof building
摘要
Abstract
To investigate the temperature rise patterns and structural responses of large-space buildings like truss roof structures under fire,a fire collapse test was conducted on an actual steel-concrete mixed truss roof building.The test utilized stacks of wood as the fire source.The thermocouples,weighbridges,microwave radars,and high-temperature resistant inclinometers were used to measure the heat release rate of the fire source,internal air temperature of the building,temperature of structural components,and the displacements and rotations of key joints.The study identified the characteristics of the temperature rise and the laws of change in displacements and rotations of the structures under real fire conditions.Field simulation and finite element methods were employed to simulate the building's air temperature field and the thermal-structural coupled response,respectively.The accuracy of the numerical simulations was validated against the test results.The study reveals that the gas temperature field of the building shows a distinctly uneven distribution.The temperature range at the measurement points is from 500℃ to 900℃.The combustion pattern of the fire source could be divided into four stages:flashover,slow rise,steady state,and decay.The variation trend of the air temperature field is generally consistent with the variation of the heat release rate.The collapse of the mixed truss roof is initiated by bending failure of the top concrete chord,which is distinctly different from the collapse mechanisms due to buckling failure in pure steel trusses.The field simulation can accurately reproduce the air temperature distribution within the truss,and the simulation accuracy increases as the distance from the fire source increasing.The measurement points far from the five source are generally consistent with the simulation results.Finite element simulation can accurately determine the collapse mode,primarily due to bending failure,and the deformation patterns of the truss.关键词
桁架/火灾/倒塌试验/场模拟/热力耦合/倒塌模式Key words
truss/fire/collapse test/field simulation/thermal-structural coupling/collapse mode分类
建筑与水利引用本文复制引用
李晋宇,杨晓琳,江黎明,聂勇峰,罗齐,李国强,朱劭骏,张超,陈彬,吉蔚,戚洪辉,王尧,陈楠..既有桁架屋盖建筑火致倒塌试验与数值模拟[J].建筑结构学报,2025,46(3):153-163,11.基金项目
上海市浦江人才计划(22PJ1414000). （22PJ1414000）
