行波效应对连续刚构桥地震响应的研究

Research on the seismic response of continuous rigid frame bridge by traveling wave effect

针对大跨度桥梁结构抗震问题的研究,以某(97+2×180+97)m大跨度加劲钢桁连续刚构桥为工程实例,根据桥址的地质条件选取一条Fernando波进行地震激励,并选取不同的视波速且计算出地震波到达各承台底的滞后时间,以此来分析行波效应对桥梁结构的影响。研究表明:对高墩大跨度加劲钢桁连续刚构桥抗震设计时,按一致激励进行地震响应分析并非总是偏于安全的,需要重视多点激励问题。

In view of the research on seismic resistance of long-span bridge structures,taking a(97+2×180+97) m long-span stiffened steel honing continuous rigid frame bridge as an engineering example,according to the geological conditions of bridge site,this paper selected a Fernando wave for seismic excitation,selected different apparent wave velocities and calculated the time lag of the seismic wave reaching the bottom of each cushion cap,to analyze the influence of traveling wave effect to bridge structure.The research showed that the seismic response analysis based on uniform excitation was not always safe for the seismic design of long-span stiffened steel continuous rigid frame bridges with high piers,and the problem of multi-point excitation should be paid attention to.