【作者】 都爱华；

【导师】 朱维申； 张鑫；

【作者基本信息】 山东大学 ， 工程力学， 2010， 博士

【摘要】 框架柱托换节点的设计是框架结构移位成功的关键技术,其受力机理非常复杂,且托换节点的承载力至今没有统一的计算公式。本文通过16组缩尺托换节点的试验,研究了托换节点的受力机理,分析了托换节点承载力的影响因素,提出了“空间拉杆拱”的力学模型,并结合混凝土结构方面的研究理论和有限元软件ABAQUS,对托换节点在界面上的受力机理进行了深入的探讨。第一,研究了行走梁剪跨比、托换梁纵筋配筋参数、托换梁箍筋配箍率、梁柱结合面插筋配筋参数、行走梁混凝土强度五种因素对托换节点破坏荷载的影响,得出行走梁剪跨比对破坏荷载的影响程度最大,其次是纵筋配筋参数和箍筋配箍率。同时对行走梁的计算模型进行简化,通过试验数据的线性回归,得出托换节点行走梁抗剪承载力的计算公式。第二,依据16组试件的破坏现象和破坏形态,探讨了托换节点在界面冲切滑移前阶段的受力机理,提出了托换节点的“空间拉杆拱”力学模型,在此基础上推导出托换节点承载力的理论公式,并与试验结果进行了对比,二者吻合较好。同时结合界面剪切理论,分析托换节点在界面冲切滑移后阶段的受力机理,在通过未裂和预裂混凝土界面剪力传递的研究成果的基础上,结合试验回归得出,托换节点的最小界面高度计算公式和最小插筋配筋量计算公式。第三,运用有限元软件ABAQUS,对试验中的两个典型托换节点进行了界面冲切滑移前阶段的有限元分析。得出托换节点界面法向应力和剪应力分布比较复杂,界面底部出现拉应力,但界面开裂范围很小；托换梁压应力呈明显的“拱形压杆”分布,拉应力呈底部“通长拉杆”分布,与本文提出的托换节点的“空间拉杆拱”力学模型吻合的很好。第四,针对已完成的5个建筑物移位工程的17个托换节点进行设计复核,得出行走梁抗剪承载力计算公式、托换节点承载力理论公式、托换节点最小界面高度计算公式和最小界面插筋配筋量计算公式的结果与工程结果吻合较好；并通过17个托换节点工程结果的再次回归,得到既能包络试验结果又能包络工程结果的行走梁抗剪承载力设计公式。更多还原

【Abstract】 Frame column underpinning joint design was a key technology to frame structure moving, but the mechanical behavior of column underpinning joint was very complex, and the calculation equation of the underpinning joint bearing capacity hadn’t been unified until today. Based on sixteen groups scale-model experiment, factors influencing bearing capacity of the underpinning joint were analysed, the mechanical behavior of column underpinning joint was discussed, at the same time, considering the theory of concrete structure and finite element software ABAQUS, a in-depth study was done on the complex mechanical behavior of column underpinning joint of frame structure.First, five factors were discussed to make sure the influence to failure load, which were moving-beam shear span ratio, underpinning beam stirrup steel bar ratio, underpinning beam longitudinal steel bar parameter, planted reinforcement parameter, and column moving-beam strength, the conclusions were drawn, that was, the first factor to the failure load was the moving-beam shear span ratio, secondly was underpinning beam longitudinal steel bar parameter, thirdly was underpinning beam stirrup steel bar ratio. At the same time, the moving-beam caculation model was simplified, considering linear regression analysis of experiment data, the moving-beam shear equation of column underpinning joint was drawn.Second, based on the failure phenomena and failure type, the mechanical behavior of the stage before interface untipunching slip of the underpinning joint was discussed. Furthermore the mechanical model "space tension bar arch" was put forward, and based on the theory, theoritical bearing capacity equation was set up, and the equation’s result was agreement with experiment’s result. At the same time, considering the theory of interface shear, the interface failure mechanism of the stage after interface untipunching slip of the underpinning joint was studied, and based on the experiment linear regression, the minimum interface height calculation equation and the minimum planted reinforcement calculation equation was drawn.Third, design check was done about seventeen underpinning joints of five completed projects of building moving, four calculation equations drawn by this paper, which was moving-beam shear equation, theoretical bearing capacity equation, the minimum interface height design equation and the minimum planted reinforcement design equation, the conclusion was drawn that the equations results were good agreement with projects results; and based on the linear regression analysis of project data, a new moving-beam shear design equation was drawn.Finally, by means of finite element software ABAQUS, the analysis of two experiment sample underpinning joints of finite element was done for the stage before interface untipunching slip, and the result was drawn,that was, interface press stress and shear stress distributing was complex, and tension stress was appeared at the bottom of interface while the cracking was small; and underpinning beam press stress distributing was like "arch press bar", and the tension press distributing was like "long tension bar" at bottom, which were good agreement with the "space tension bar arch" model put forward by this paper.更多还原