火灾下门式钢刚架倒塌预测关键易测参量与预警方法

近年来火灾下钢结构倒塌事故频繁发生，严重威胁消防救援官兵和人民群众的生命财产安全，引起国家应急管理部消防救援局的高度关注，亟需开展建筑火灾倒塌预警方法研究。文章基于足尺结构受火试验数据和参数化数值分析结果，提出火灾下门式钢刚架的四种典型倒塌模式，重点研究不同倒塌模式下结构关键易测参量的变化规律，确定了可用于预测火灾下门式钢刚架结构倒塌可能性的预警判定指标，包括火灾下门式钢刚架结构柱顶檐口和跨中屋脊处水平及竖向变形(位移)、变形速率及结构受火构件最高温度等指标，进而提出适用于门式钢刚架多种倒塌模式的预警方法，为结构倒塌预警系统的建立提供一条有效途径。研究表明，提出的预警方法可快速有序地进行火灾下门式钢刚架倒塌的预测预警，其准确性及适用性也得到已有试验的验证。

Easy-measured key parameters and early-warning methods for the #br# collapse prediction of steel portal frames under fire

 In recent years, the collapse of steel structures under fire has frequently occurred, which not only caused property damage to residents, but also seriously threatened the lives of residents and firefighters. It has drawn great attention from the Fire Rescue Bureau of Emergency Management Department. Therefore, it is urgent to carry out the research on early-warning method for building collapse under fire. Based on full-scale fire test data and numerical simulation results, four typical collapse modes are summarized, and the change law of easy-measured key parameters of the structure under different collapse modes is specially studied. The early-warning indexes used for predicting the collapse probability of steel portal frames are determined, including horizontal and vertical deformation (displacement) and deformation rate at the location of two eaves and the apex, as well as maximum temperature of the structural steel elements during the fire, and then the early-warning methods applicable to different collapse modes of steel portal frames are proposed, providing an effective way for the establishment of structural collapse warning systems. The results show that the proposed early-warning method can easily predict the collapse of the steel portal frame under fire, and its accuracy and applicability have also been verified by experiments.