大跨度连续梁桥在不同激励方式下地震响应

Seismic analysis of long-span continuous girder bridge under different incentive methods

为解决大跨度连续梁桥抗震设计理论不完善的问题,以六库怒江大桥为工程背景,采用MIDAS/CIVIL有限元软件建立三跨混凝土连续梁桥有限元模型,分别进行反应谱一致激励、时程一致激励和时程多点激励,在不同激励方法条件下大对跨度桥梁地震反应进行对比分析.结果表明:反应谱法在桥梁抗震响应分析中存在局限性,在对大跨度连续桥梁地震响应分析中考虑时程多点激励才能更真实地反应出结构的地震响应.

In order to solve the problem of imperfect seismic design theory of large-span continuous girder bridge, this paper focuses on the basic principles of seismic analysis of bridge response spectrum method and time history analysis method on the engineering background of Liuku Nujiang river Bridge. This study applies the finite element software MIDAS/CIVIL, sets up finite element model of three-span concrete continuous girder bridge, and gets the corresponding seismic response of bridge structure by using response spectra consistent motivation, time-consistent incentive and time multi-support excitation, and follows by comparing the result of the analysis under three kinds of incentives. The result points out the limitation of application of bridge seismic response spectrum method, which suggests taking into account of the effect of multi-support excitation on bridge structure.