以5层钢框架结构为对象,对钢框架在爆炸冲击作用下的连续倒塌性能进行了研究.采用备用荷载路径法,分别对钢框架结构进行了静力非线性、动力非线性以及爆炸冲击作用下的动力非线性连续倒塌分析.分析结果表明:在常规的静力和动力非线性分析中,该框架具有良好的抗连续倒塌能力;在5 kg TNT的初始爆炸冲击作用下,钢框架的变形比常规分析增大15%~40%;在15 kg TNT的爆炸冲击作用下,钢框架将发生整体性倒塌.因此传统的备用荷载路径法不适用于分析爆炸引起的连续倒塌问题,爆炸冲击的作用不可忽略;楼板在爆炸作用下对结构的连续倒塌性能有着至关重要的影响.
Taking a five-storey steel frame structure as an example,a study of progressive collapse performance of multi-storey steel frame subjected to the explosion loads was carried out.Using alternate path method,three analysis conditions were considered: static nonlinear analysis,dynamic nonlinear analysis and dynamic nonlinear analysis with blast effects.Simulation results show that: in conventional static nonlinear and dynamic nonlinear analysis,the steel frame has a good ability to resist progressive collapse;under 5kg TNT explosive impact,deformation of the steel frame is 15% to 40% more than using conventional analysis,and large-scale collapse of the frame will occur when explosive load increases to 15kg TNT.Therefore,conventional alternate path method is not suitable for progressive collapse analysis with blast effects and explosive impact on structure members can not be ignored.Floor has crucial influence on progressive collapse performance for steel frame with blast effects.