钢管混凝土拱桥不同拱肋截面参数下的力学性能研究

Study on Mechanical Properties of Steel Tubular Arch Bridge under Different Arch Rib Section Parameters

以某钢管混凝土拱桥为对象,利用桥梁专用有限元程序Midas Civil建立全桥空间有限元模型,分自重、自重+活载两种工况,计算对比了三种不同拱肋截面参数下结构的静力性能、动力性能和稳定性能。研究结果表明:横哑铃型拱肋(缀板填混凝土)结构与横哑铃型拱肋(缀板不填混凝土)结构在吊杆受力方面区别较小,相同工况下的横哑铃型拱肋(缀板不填混凝土)所受轴力以及正挠度均小于前者;四肢桁架拱的位移与前两者相差较大,其负挠度过大;在动力方面,横哑铃型拱肋(缀板填混凝土)与横哑铃型拱肋(缀板不填混凝土)的自振频率和振型相似,后者基频更高;四肢桁架拱的刚度较低,其自振频率下降较大;在稳定性方面,横哑铃型拱肋(缀板填混凝土)的特征值略高于横哑铃型拱肋(缀板不填混凝土),四肢桁架拱的特征值过小。

In this paper, the concrete - filled steel tubular arch bridge is used as the research object, and the finite element model of the full bridge is established by using the finite element program of the bridge. The static performance, dynamic performance and stability of the three different arch rib parameters under the parameters of self - weight, self - weight and live load are compared. The results show that： horizontal dumbbell - shaped arch ribs （filled with concrete） structure and horizontal dumbbell - shaped ribs （not filled with concrete） structure in the boom force difference is small, under the same conditions of the horizontal dumbbell - shaped arch ribs （ not filled concrete） suffered axial force and positive deflection are less than the former, the displacement of the limbs truss arch is quite different from that of the first two, its negative deflection is too large. In terms of dynamic performance, the horizontal dumbbell - shaped ribs （filled with concrete） and the horizontal dumbbell - shaped ribs （not filled with concrete） are similar to the natural frequencies and modes, the latter is higher frequency, the stiffness of the limbs truss arch is low, and its natural frequency decreases greatly. In terms of stability, the characteristic value of the horizontal dumbbell - shaped arch ribs （filled with concrete） is slightly higher than that of the horizontal dumbbell - shaped arch ribs （not filled with concrete）, the characteristic values of the limbs truss arch are too small.