拱肋刚度的选取对钢管混凝土拱桥稳定计算的影响

首先介绍了钢管混凝土拱桥线性和非线性稳定计算理论,为了对比不同拱肋刚度计算方法对钢管混凝土拱桥稳定系数计算的影响,以章江大桥为例,分别采用3种钢管拱肋刚度计算方法,使用有限元程序ANSYS对成桥运营阶段第1类稳定和第2类极值点稳定进行了分析。结果表明,考虑几何非线性、材料非线性和初始缺陷的非线性稳定的失稳荷载比线性屈曲计算值要小很多;换算截面法和试验数据法计算结果中的弹性稳定系数和非线性稳定系数比较接近,而采用复合材料法计算结果与两者相差较大;采用试验数据法模拟钢管拱肋刚度计算结果中无论弹性稳定系数还是非线性稳定系数都较为安全。

Influence of Steel-concrete Pipe Arch Rib Rigidity on Stability of Concrete-filled Steel Tube Bridge

The linear and nonlinear buckling theory of concrete-filled steel tube bridge was presented.In order to compare the different calculated stability coefficients for the bridge by different calculation methods of arch rib rigidity,the FEM model of Zhang Jiang bridge,as an example,was set up,and the first stability and the second extremum stability during service of the bridge were analyzed using 3 calculation methods on the rigidity of steel-concrete pipe arch rib.The results show that,the load result of nonlinear stability considering geometry nonlinearity,material nonlinearity and initial defects of the structure is less than the value considering linear bucking result.The results of elastic coefficient of stability and nonlinear coefficient calculated from the conversion section method and the method using experimental data is closer than the results with the composite materials method.The results also show that the method using test data is the safest one for computation of stability and nonlinear stability.