某下承式钢管混凝土拱桥抗震分析

根据郑州黄河公路二桥的结构特点建立了桥梁空间有限元计算模型,计算了该桥考虑吊杆张力和拱肋初应力影响的动力特性和地震响应,并与不计吊杆张力和拱肋初应力影响的桥梁动力特性和地震响应进行了比较.计算结果表明,初应力对郑州黄河公路二桥的频率有一定的影响,但对各阶频率的影响程度不同,对第2阶频率影响最大,下降8.8%;水平地震作用下,初应力对主拱肋的轴力、剪力和弯矩影响不大;主拱肋的内力和变形都满足设计要求,说明该桥抗震性能良好.

Anti-seismic Analysis of a Through Concrete-filled Steel Tubular Arch Bridge

The 2nd Yellow River highway bridge in Zhengzhou is a large-span concrete-filled steel tubular(CFST) arch bridge with tie bars.A three-dimension finite element model is established in terms of the structure characteristics of CFST arch bridge,and dynamic characteristics and the seismic responses derived from history analysis are analyzed and compared under initial stress or not.The results show that the initial stress affects the natural frequency to some extent,but their influence extent to each frequency is different,that the initial stress affects lesser the axis force,shear and moment of arch-ring under lever seismic wave.The anti-seismic capability of the bridge is all right,because the internal forces and displacement of arch-ring are less than design value.