大跨拱桥水平地震行波反应计算的一致反应谱方法  

Consistent Response Spectrum Method for Horizontally Travelling Seismic Wave Response Analysis of Long-span Arch Bridges

作　　者：楼梦麟[1] 唐玉[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《防灾减灾工程学报》2013年第2期119-124,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：科技部国家重点实验室基础研究项目(SLDRCE08-A-07);国家自然科学基金项目(90915011)资助

摘　　要：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。Regarding to the nature of longspan arctl ortage b by1,, j J seismic response analysis of the arch bridge under horizontal travelling seismic wave excitation was decomposed into two dynamic equations for consistent seismic response analysis of symmetri cal and asymmetrical semiarch bridges. A new concept of symmetrical and asymmetrical compo nent response spectra for travelling seismic wave was developed. The spectrum features of the symmetrical and asymmetrical components of travelling seismic wave were discussed by using ac tual earthquake records considering different types of site. Numerical analysis results show that the spectra of symmetrical and asymmetrical components of the travelling seismic wave have same shape with that of original seismic wave. Based on establishing the acceleration amplitude^s attenuation relations of the symmetrical and asymmetrical components of travelling seismic wave and combining with the consistent seismic design spectra in current codes, the consistent re sponse spectrum method for horizontal seismic travelling wave response analysis of the longspan symmetrical arch bridges was suggested. The results of numerical example demonstrate that the calculation precision of the suggested method has a same level with the consistent response spec trum method being applied currently in engineering. The calculation can be significantly simpli fied so that the method is easy to use in engineering. The method can also be applied to the case of the dynamic response analysis of arch bridge under vertical seismic travelling wave excitation.

关 键 词：大跨度拱桥 行波效应 一致反应谱法 时程分析 

分 类 号：P315.9[天文地球—地震学]