钢桁腹杆PC组合箱梁桥自振特性研究

Study on Natural Vibration Characteristics of Steel Truss Web Member Pre-stressed Concrete(PC) Composite Box Girder Bridge

为研究钢桁腹杆预应力混凝土(PC)组合箱梁桥自振特性,以一座三跨连续波形钢腹板PC组合箱梁桥为背景工程,将原箱梁中的波形钢腹板用钢桁腹杆代替,进行钢桁腹杆PC组合箱梁桥的设计。利用ANSYS和Midas Civil两种分析软件建立三维有限元模型,分析该桥型的自振特性。以横隔板的布置为参数,研究其对钢桁腹杆PC组合箱梁桥自振特性的影响。结果表明:钢桁腹杆PC组合箱梁桥竖弯刚度小,抗扭刚度大;布置横隔板对钢桁腹杆PC组合箱梁桥的竖弯刚度影响不大,对箱梁的横弯刚度和抗扭刚度有一定影响,且当对横隔板进行合理布置时,箱梁的抗扭刚度提高明显。

To study the natural vibration characteristics of steel truss web member PC composite box girder bridge, and based on the background engineering of a three-span continuous waveform steel web PC composite box girder bridge, the steel truss web member is used to replace the waveform steel web in the original box girder and the steel truss web member PC composite box girder bridge is designed. Two analysis software ANSYS and Midas Civil are used to establish a three-dimensional finite element model to analyze the natural vibration characteristics of this bridge. The influences of diaphragms set up as the parameter on the natural vibration characteristics of steel truss web member PC composite box girder bridge are studied.The results show that the vertical bending stiffness of the steel truss web member PC composite box girder bridge is small, and the torsional stiffness is large. The setup of the diaphragm has a little influence on the vertical bending stiffness of this bridge, but has a certain influence on the cross bending stiffness and torsional stiffness of the box girder. Moreover, the torsional stiffness of box girder is obviously improved when the diaphragm is reasonably set up.