【作者】 高秋利；

【导师】 李忠献；

【作者基本信息】 天津大学 ， 建筑工程技术与管理， 2011， 博士

【摘要】 碗扣式钢管脚手架作为建筑施工的一种新型脚手架体系,应用广泛。然而多年来碗扣式钢管脚手架设计一直沿用扣件式钢管脚手架规范,使碗扣式钢管脚手架设计无据可依。本文以主编我国《建筑碗扣式钢管脚手架安全技术规范》(JGJ166-2008)为契机,依托河北省建设科技研究计划项目“碗扣式钢管脚手架整体结构荷载试验研究”,对碗扣式钢管脚手架和模版支撑架分别进行了整体结构承载力试验研究和有限元数值分析,主要研究内容和成果如下。(1)设计了6组双排碗扣式钢管脚手架极限承载力试验方案,比较竖向荷载单独作用以及竖向荷载和水平荷载共同作用下脚手架的极限承载力和破坏模式,得到设置水平斜杆和廊道斜杆对脚手架极限承载力和破坏模式的影响规律。试验结果表明,水平荷载作用下脚手架面外位移增大,承载力降低;设置水平斜杆和廊道斜杆可显著提高脚手架承载力,有效减小脚手架变形。(2)设计了8组碗扣式钢管模板支撑架极限承载力试验方案,比较国标碗扣与非国标碗扣钢管模板支撑架破坏模式和承载力,得到设置水平及竖向剪力撑的支撑架极限承载力和破坏模式,以及立杆步距、天杆高度和高宽比对支撑架极限承载力和破坏模式的影响。试验结果表明,采用非国标碗扣的钢管模板支撑架极限承载力由节点强度控制,国标碗扣的钢管模板支撑架的破坏形式为整体失稳破坏;当其他条件相同时,天杆高度、高宽比、步距增大时,支撑架承载力降低;同时设置水平及竖向剪力撑时将有效提高支撑架极限承载力。(3)设计了2组碗扣节点受力性能试验方案,比较国标与非国标碗扣节点性能,得到碗扣节点与脚手架破坏先后顺序,分析碗扣节点的刚度。试验结果表明,非国标碗扣承载力由强度控制;国标碗扣节点脚手架杆件先于碗扣发生屈服,碗扣节点受力性能良好,碗扣节点为半刚性连接节点。(4)按空间铰结体系建立碗扣式钢管脚手架和模板支撑架有限元模型,分析其极限承载力和破坏模式,并与试验结果进行对比。根据碗扣式脚手架与模板支撑架承载力试验结果与有限元分析结果,给出了碗扣式脚手架杆件计算长度的计算公式。本文研究成果可为编制《建筑碗扣式钢管脚手架安全技术规范》(JGJ166-2008)提供试验数据和理论依据,亦可为碗扣式钢管脚手架和模板支撑架设计提供参考。更多还原

【Abstract】 A new type scaffolding, the Buckles bowl scaffold is widely used nowadays. But the buckles bowl scaffold is following the Specifications of Tube-and-coupler Scaffold, and this brings problems on security.The author take the opportunity of editing the Safety and technical code for frame scaffoldings with Buckles Bowl in construction(JG166-2008), and based on the science project of Hebei provincial construction technology research & test on load of the overall structure of buckles bowl scaffold, studied the overall load of external scaffolding and internal braced frame of buckles bowl scaffold, and analyzed the ultimate bearing capacity. The main contents and results are as follows:(1) 6 groups of double buckles bowl scaffolds are designed. The ultimate bearing capacities and damage modes of the test specimens subjected to vertical loads and both horizontal and vertical loads are compared, and the influence regularities to the ultimate bearing capacities and damage modes of scaffolds led by horizontal diagonals and covered diagonals are obtained. Experimental results show that the horizontal load has more influence to bearing capacity and deformation of the scaffold, and it can significantly improve the bearing capacity and reduce the deformation when horizontal diagonals and covered diagonals are installed.(2) 8 groups of double buckles template braced frames are designed. The ultimate bearing capacities and damage modes of the national standard and the non national standard template braced frames are compared, and the influence regularities to the ultimate bearing capacities and damage modes of scaffolds led by horizontal diagonals, covered diagonals, bar gap, height, and aspect ratio are obtained. Experimental results show that the bearing capacity of non national standard template braced frame relay on the strength of joint, and the national standard template braced frame has a damage mode of overall instability. Bearing capacity of the braced frame decreases with the increment of the height, the gap and the aspect ratio of the bracing piece. Bearing capacity of the braced frame will increase efficiently if both the horizontal and vertical brace are installed.(3) 2 groups of buckles bowl joints are designed. Mechanical behaviors of national standard and non national standard buckles bowl joints are compared, and the damage order of buckles bowl joints and scaffold are obtained. The stiffness of buckles bowl joints are analyzed. Experimental results show that the bearing capacity of non national standard scaffold is determined by strength, and the damage of scaffold precedes to the damage of national standard buckles bowl joints. The buckles bowl joint, which is a semi-rigid connection, has a good mechanical behavior.(4) Ultimate bearing capacities and damage modes of bowl buckle scaffold and template brace are analyzed by finite element method and numerical results are compared with the experimental results. The calculation length formula of the member of bowl buckle scaffold is given.Achievements of this paper supply experimental and theoretical references for both the written of Safety and technical code for frame scaffoldings with Buckles Bowl in construction(JG166-2008)and design of the buckles bowl scaffold and the template braced frame.更多还原