【作者】 李晓辉；

【导师】 陈宝春；

【作者基本信息】 福州大学 ， 桥梁与隧道工程， 2011， 博士

【摘要】 钢管混凝土拱桥在我国已大量应用于现代桥梁工程中，在此类拱桥结构体系中，钢管混凝土实肋拱（单圆管与哑铃形）的数量较多，约占一半以上的比例。作为主要承重结构的钢管混凝土拱肋在竖向（面内）有着良好的承载性能，然而由于面外刚度通常相对较弱，面外稳定往往成为主要的问题。因此，本文从钢管混凝土结构的组合受力性能出发，对实肋拱的面外稳定问题进行研究，主要工作与成果如下：（1）由于拱的面外失稳含有扭矩作用，进行了钢管混凝土实肋拱截面受扭性能研究，检验了截面受扭分析的有限元方法。开展了哑铃形拱在空间荷载作用下的受力性能试验研究，得到面外失稳全过程的试验现象，并应用有限元方法，建立了钢管混凝土实肋拱的面外稳定分析的实体空间有限元模型。（2）开展了实肋拱弹性特征值屈曲失稳和双重非线性极值点失稳的分析，探讨了各相关因素对钢管混凝土实肋拱面外稳定性能的影响。研究结果表明，在几何参数中，面外长细比是影响实肋拱面外稳定性能的最大因素，面外失稳临界荷载随着面外长细比的增加而呈非线性递减。矢跨比也是一个重要参数，面外失稳临界总荷载随着矢跨比的增加而提高，但提高到一定程度后趋于平缓。不同材料参数均会影响到面外稳定承载力，其中含钢率因素影响较为显著。另外，面外弹性特征值屈曲分析无法真实地反映有水平横向力或面外初始几何缺陷情况下的实肋拱面外稳定性能，应使用非线性极值点失稳分析方法来计算面外稳定承载力。（3）进行了钢管混凝土实肋拱在竖向四种基本加载方式作用下的面外稳定性能分析。其中全跨均布荷载作用下的面外失稳临界总荷载最大，半跨均布荷载下的次之。加载方式对单圆管拱的面外稳定承载力影响较为显著。哑铃形拱的面外稳定承载力通常高于相应单圆管拱的面外稳定承载力。（4）提出了钢管混凝土实肋拱的面外失稳临界荷载的稳定系数实用算法。文中通过建议的面外等效长度系数，应用欧拉公式进行面外特征值屈曲临界荷载的计算。通过Perry-Robertson公式的形式来表示面外稳定系数与面外正则化长细比之间的关系，从而计算拱的面外稳定极限承载力。同时，本文给出了面外弹性屈曲系数与面外稳定系数的比值曲线，也可以由面外弹性屈曲临界荷载来确定拱的面外稳定极限承载力。更多还原

【Abstract】 Concrete-filled steel tubular (CFST) arches have been broadly used in modernbridge engineering in China. Among various CFST arches, single steel tubular anddumbbell-shaped CFST arches, which are called solid rib arches, are accounted alarge part of the total. As the main bearing structure, CFST arches usually haveexcellent in-plane load-carrying capacity compared, however because the relativelyweak out-of-plane rigidity, the out-of-plane stability often arise as the dominateproblem. Therefore, this thesis focuses on the out-of-plane stability of CFST solidrib arches, starting from the study on composite mechanical behavior of CFSTstructures. The main work and research results are as follows.Firstly, single tubular and dumbbell-shaped CFST specimen subjected totorsion moments are carried out, and a finite element method to analyze it is verifiedby the test results. Then experimental of dumbbell-shaped arch model under spatialloading is conducted and the whole behaviors of the model to failure are obtained. Aspatial finite elements model is built to analyze the out-of-plane stability of theCFST solid rib arches.Secondly, instability due to elastic buckling and peak value (ultimateload-carrying capacity considering the stability problem) are analyzed bycalculation of Eigen value and FEM method taking into account the dual nonlinearproblem (material nonlinearity and geometric nonlinearity). The influences ofvarious parameters to the out-of-plane stability are discussed. The analysis resultsshow that out-of-plane slenderness ratio is the most important among all theparameters and the out-of-plane critical load takes a nonlinear decrease as theout-of-plane slenderness ratio increases. Rise-span ratio is another important factor.The total critical load increases with the increase of the rise-span ratio, but it willincrease smoothly not significantly when the rise-span reaches to some value.Moreover, different material parameters have different influences on out-of-planestability, in which the steel ratio has the most significant affect. In addition, elasticbuckling analysis may give a false result when the arch subjected to a out-of-plane force or the arch has an initial out-of-plane geometric imperfection. In this case, thecritical load of the arch failure by out-of-plane instability should be calculated bythe FEM analytical method which considering the double nonlinearity.Thirdly, the thesis is also focused on the analysis of the out-of-plane stabilityunder four basic kinds of loading conditions. The sum value of the critical load ofthe out-of-plane stability of the arch is the largest one when the arch subjected towhole-span uniform load, and it is the second one when the arch is subjected to thehalf-span uniform load. The out-of-plane stability is influenced greater to an archwith single tube section than to an arch with dumbbell-shaped section. Furthermore,the out-of-plane stability of dumbbell-shaped arches is generally higher than that ofthe single steel tube arches.Finally, the thesis puts forward a simplified algorithm about the out-of-planecritical load of CFST solid arches. According to the suggested out-of-planeequivalent length coefficient, Euler formula is applied to calculate the out-of-planebuckling load. Besides, Perry-Robertson formula is used to express the relationshipbetween out-of-plane stability coefficient and out-of-plane normalized slendernessratio, and hence the out-of-plane stability ultimate load-carrying capacity can befurther calculated. Meanwhile, the ratio curve between out-of-plane elastic bucklingcoefficient and out-of-plane stability coefficient is given. The out-of-plane stabilityultimate load-carrying capacity also can be calculated by the out-of-plane elasticbuckling critical load.更多还原