钢支撑对多层钢框架结构抗连续倒塌鲁棒性影响研究  

Influence of steel braces on robustness of multilayer steel frames against progressive collapse

作　　者：李治 薛天琦 李光涛 蓝希 钱凯 LI Zhi;XUE Tianqi;LI Guangtao;LAN Xi;QIAN Kai(Guangxi Key Laboratory of New Energy and Building Energy Saving,Guilin University of Technology,Guilin 541004,China;College of Civil Engineering and Architecture,Guilin University of Technology,Guilin 541004,China;College of Civil Engineering and Architecture,Guangxi University,Nanning 530000,China)

机构地区：[1]桂林理工大学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 [3]广西大学土木建筑工程学院,广西南宁530000

出　　处：《建筑结构学报》2023年第4期257-266,共10页Journal of Building Structures

基　　金：国家自然科学基金优秀青年基金项目(52022024);广西自然科学基金项目(2022GXNSFBA035628);广西建筑新能源与节能重点实验室开发基金(桂科能22-J-21-5、22-J-21-3);广西中青年科研基础能力提升项目(2021KY0254)。

摘　　要：为研究钢支撑对钢框架结构抗连续倒塌鲁棒性的影响,制作了两个1/2缩尺的二层钢框架子结构,其中一个框架布置钢支撑,另一个为纯框架。试验采用位移控制的Pushdown加载方式,对多层钢框架的抗力机制、内力变化以及破坏模式进行研究。试验结果表明:布置钢支撑后,钢框架子结构的初始刚度和极限荷载分别提升129.7%和45.1%,明显提高了钢结构抗连续倒塌的鲁棒性;由于受压支撑在加载初期就开始发生局部屈曲,较早失去承载能力,钢支撑的抗力贡献主要由受拉支撑提供。通过有限元分析软件ANSYS/LS-DYNA进一步研究了钢支撑布置位置及其截面尺寸对钢框架抗连续倒塌性能的影响,分析结果表明:增大钢支撑的截面尺寸可以明显提高钢框架的承载力,但会降低其变形能力;将钢支撑布置于失效柱上层或顶层时对钢框架的加固效果较好;由于去柱楼层的不确定,建议将钢支撑布置于顶层对框架抗倒塌更为有利。In order to study the influence of steel bracing on the robustness of steel frame against progressive collapse,two two-story steel frame substructures with one-half scale were made.One specimen was equipped with steel bracing,and the other specimen was a bare frame.The resistance mechanism,internal force and failure mode of multilayer steel frames were studied by employing Pushdown loading method controlled by displacement.The experimental results show that the initial stiffness and ultimate load of steel frame are increased by 129.7%and 45.1%,respectively when the steel bracing is laid out and the robustness of steel structure against progressive collapse is obviously improved.Due to the local buckling of the compression bracing at the early stage,the bearing capacity of the steel bracing is lost earlier,and the contribution of the resistance of the steel bracing is mainly provided by the tension bracing.Then,the influence of the position and size of steel bracing on the progressive collapse resistance of steel frame was further studied by using finite element analysis software ANSYS/LS-DYNA.The finite element analysis results show that increasing the section size of steel bracing can obviously improve the ultimate bearing capacity of steel frame,but reduce its deformation capacity.The reinforcement effect of steel structure is better when steel bracing is placed on the upper or top layer of removed column.Due to the uncertainty of column removal stories,it is suggested to install steel bracing on the top story,which is more favorable for the structure to resist collapse.

关 键 词：钢框架 钢支撑 Pushdown试验 有限元分析 抗连续倒塌 鲁棒性 

分 类 号：TU391[建筑科学—结构工程] TU317.1