不同去柱工况下多层钢框架结构抗连续倒塌机理研究  

BEHAVIOR OF PROGRESSIVE COLLAPSE OF MULTI-LAYER STEEL FRAME STRUCTURE UNDER DIFFERENT COLUMN REMOVAL CONDITIONS

作　　者：李治 原小兰 薛天琦 钱凯 LI Zhi;YUAN Xiao-lan;XUE Tian-qi;QIAN Kai(Guangxi Key Laboratory of New Energy and Building Energy Saving,Guilin University of Technology,Guilin,Guangxi 541004,China;College of Civil Engineering and Architecture,Guilin University of Technology,Guilin,Guangxi 541004,China)

机构地区：[1]广西建筑新能源与节能重点实验室,广西桂林541004 [2]桂林理工大学土木建筑工程学院,广西桂林541004

出　　处：《工程力学》2024年第4期140-150,共11页Engineering Mechanics

基　　金：国家自然科学基金优秀青年基金项目(52022024);广西科技基地和人才专项项目(2021AC19076);广西建筑新能源与节能重点实验室开发基金项目(桂科能22-J-21-3);广西中青年科研基础能力提升项目(2021KY0254)。

摘　　要：为探究不同去柱工况对多层钢框架结构抗连续倒塌性能影响,分别对中柱失效和角柱失效工况的2层2跨钢框架梁-柱子结构进行Pushdown加载试验,研究其在倒塌过程中的抗力曲线和破坏模式。试验结果表明:中柱失效下钢框架主要依靠弯曲机制和悬链线机制抵抗外加荷载,且悬链线机制具有一定的滞后性;而角柱失效下钢框架主要依靠弯曲机制抵抗倒塌,且由于空腹效应的存在,可以有效提高结构的抗倒塌承载力。随后通过有限元软件ANSYS/LS-DYNA对所研究试件进行数值模拟,并对现实场景中可能出现的6种去柱工况分别进行抗连续倒塌分析。通过对比6种去柱工况钢框架结构的抗力曲线和抗倒塌风险可知:不同去柱工况下的钢框架结构水平约束条件不同,从而空腹效应发展也不尽相同;考虑空腹效应并考虑单位面积结构的承载力时,邻角柱失效与邻边柱失效工况下的钢框架结构具有较高的倒塌风险。To study the behavior of progressive collapse of multi-layer steel frame under different column removal scenarios,pushdown tests were carried out on two-storey two-span steel frame beam-column substructures with middle column failure and corner column failure,respectively.The resistance curves and failure modes in the collapse process were studied.The test results showed that in the middle column failure condition,the steel frame mainly relies on the bending mechanism and catenary mechanism to resist the external load,and the catenary mechanism has a certain lag.In the case of corner column failure,the steel frame mainly relies on bending mechanism to resist collapse.Furthermore,its resistance to collapse is improved due to the existence of Vierendeel mechanism.Then the finite element software ANSYS/LS-DYNA was used to simulate the specimens,and the progressive collapse analysis of six possible column removal conditions in the steel frame was carried out.By comparing the resistance curves and collapse risk of six column removal conditions structures,it can be seen that the horizontal constraint condition of steel frame is different under different column removal scenarios,so the development of Vierendeel mechanism is different.Considering the Vierendeel mechanism and bearing capacity of structure per unit area,the steel frame with penultimate corner column failure and penultimate edge column failure has the highest collapse risk.

关 键 词：钢框架结构 不同去柱工况 Pushdown试验 有限元分析 连续倒塌 

分 类 号：TU394[建筑科学—结构工程] TU311.41