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针对大跨度拱桥具有对称性的特点,把水平地震行波作用下拱桥地震反应计算的动力方程分解为正、反对称半拱桥的一致地震反应计算的2个动力方程,并提出了考虑行波效应的输入地震正、反对称分量反应谱的新概念。应用与场地类型有关的实际地震记录,讨论了不同地震行波正、反对称分量反应谱的特点。数值分析结果表明,地震行波正、反对称分量具有与原地震波相同形状的反应谱。在建立地震行波正、反对称分量加速度幅值衰减关系的基础上,与常规的一致反应谱方法相结合,建立了大跨度对称拱桥水平地震行波反应计算的一致反应谱方法。算例结果表明,这一方法的精度与目前地震一致输入下反应谱方法的计算精度相当,可使得计算工作大为简化,且便于工程应用。此方法同样适用于拱桥竖向地震行波反应计算。
Considering the symmetry characteristics of long-span arch bridge, the dynamic equation of earthquake response of arch bridge under horizontal seismic waves is decomposed into two dynamic equations of uniform seismic response of the positive and anti-symmetrical half-arch bridge. The dynamic equation considering the traveling wave effect The new concept of positive and antisymmetric component response spectra of input earthquakes. The actual seismic records related to site types are used to discuss the characteristics of the response spectra of the positive and antisymmetric component of the traveling waves of different earthquakes. Numerical analysis shows that the positive and antisymmetric components of the seismic traveling wave have the same response spectrum as the original seismic wave. On the basis of establishing the relationship between amplitude attenuation of antisymmetrical component acceleration and traveling wave of seismic line, a uniform response spectrum method for calculating horizontal seismic traveling wave response of long-span symmetrical arch bridge is established in combination with the conventional uniform response spectrum method. The results show that the accuracy of this method is equivalent to that of the conventional method of response spectrum under seismic input. Therefore, the calculation work is greatly simplified and it is convenient for engineering application. This method is also applicable to the calculation of vertical seismic traveling wave response of arch bridge.