【摘要】 针对整体式桥台曲线箱梁桥的结构特点,运用结构分析软件ANSYS的APDL语言实现多模态反应谱法的自动迭代,以简化该类桥梁的动力特性分析。对该类桥梁的计算模型及影响其动力特性的主要参数进行了分析,通过动态时程分析法比较了迭代多模态反应谱法的可行性和准确性。结果表明:该类桥梁不存在纯粹某一方向的振型;1阶横弯、1阶纵弯和3阶竖弯分别对横、纵和竖向的振型贡献最大;1阶横弯和1阶纵弯频率受台后土及桩侧土密实度的影响最大,其次是地震激励频率和桥宽;3阶竖弯频率基本不受各种参数的影响;迭代多模态反应谱法可以作为该类桥梁抗震计算的一种估算手段。更多还原

【Abstract】 In order to simplify analysis of the dynamic characteristics of the integral abutment curved box girder bridge,automatic iteration of the multimode modal response spectrum(MMRS) was realized by APDL language of the structure analysis software ANSYS according to the bridge’s structural characteristics.The computation model and the main parameters influencing dynamic characteristics of the bridge were discussed.The availability and precision of the iterative MMRS method were examined by the time-history analysis.The result shows that(1) there is no pure modal shape in a certain direction;(2) 1st order transverse bending,1st order longitudinal bending and 3rd order vertical bending are most contribution to respective modes;(3) vibration frequencies of 1st order transverse bending and 1st order longitudinal bending are most influenced by compactness of back-abutment and pile-around soil,frequency of seismic excitation and the width of bridge are the next influencing parameters;(4)diversified parameters effect on frequency of 3rd order vertical bending rarely.The feasibility and veracity of the iterative MMRS are validated by the time-history analysis.The iterative MMRS can be used as an estimating method of seismic analysis for the bridge.更多还原