【摘要】 弹塑性时程分析方法是计算桥梁结构地震响应较为严格的分析方法,但该方法工作量大,计算复杂,不利于工程师进行结构设计。采用基于模态的Pushover分析方法(MPA法),对某高墩连续刚构桥梁进行抗震性能分析,根据建筑结构设计规范,要求振型参与质量之和需达到90%。通过理论分析,提出以振型贡献率提取振型参与计算的加载模式,剔除振型贡献参与质量比低于1%的振型,对高墩大跨连续刚构桥进行了推覆分析。这样既避免了全部模态参与计算的繁琐,又考虑了高阶振型的影响,并与弹塑性时程响应结果进行了对比。计算结果表明,修改的MPA法(MMPA法)应用于高墩连续刚构桥的抗震性能分析是可行的。更多还原

【Abstract】 To solve the problem of complicatedness and large amount of computations in elastic-plactic time history analysis,a mode-based pushover analysis method(MPA method) was developed to analyse.The antiseismic performance of a continuous rigid frame bridge with high piers.According to the construction design codes in China,the sum of participating masses of concerned vibration modes should exceed 90% of the total structural mass.Based on the modal participation mass ratios,some high order vibration modes were taken into account in the analysis while those vibration modes with the modal participation mass ratio less than 1% were neglected.In this way,the large amount of computations can be avoided while the effect of high order modes can be considered.The MMPS method(modified mode-based pushover analysis method) was thus developed.A comparison between the MMPA method and the elastic-plastic time-history method was made.The result shows that the proposed method(MMPA method) is of a satisfactory accuracy.It is an easy-use method for bridge engineers.更多还原