近断层地震作用下大跨度拱桥响应研究

发布时间：2019-06-04 17:40

【摘要】：目的对比研究近场地震作用下大跨度拱桥采用7组时程波的计算结果平均值与采用3组时程波的计算结果最大值的差异,为近断层地区大跨度拱桥的抗震设计提供参考.方法针对某大跨度拱桥建立有限元分析模型,在PEER数据库选取近场地震作用并施加于拱桥,得到时程响应的峰值.针对现行规范7组波作用时响应峰值的平均值与采用3组波组合时计算结果的最大值以及7组近场和远场地震作用的响应峰值的平均值进行对比研究.结果采用3组近场地震波组合计算所得的拱顶竖向位移、拱顶轴力、拱脚弯矩和跨中吊杆内力响应最小值分别是7组近场地震波计算结果平均值的0.42倍、0.48倍、0.79倍、0.75倍;采用3组近场地震波组合计算所得的四项响应最大值分别是7组近场地震波计算结果平均值的2.7倍、2.8倍、1.9倍、1.5倍.7组近场地震波作用所得的四项响应峰值的平均值分别是远场地震作用相应值的0.82倍、0.85倍、0.61倍和0.61倍.结论对于Ⅲ类场地的大跨度拱桥,按照规范规定采用3组近场地震波进行响应计算时,3组地震响应结果的最大值与按7组地震波计算结果的平均值之间存在很大差异、离散性很大;采用7组地震波进行时程响应计算时,近场地震响应峰值的平均值小于远场的平均值.
[Abstract]:Objective to compare the difference between the average value of the calculated results of seven groups of time range waves and the maximum values of three groups of time range waves in long-span arch bridges under near-field earthquakes, so as to provide a reference for the seismic design of long-span arch bridges in near-fault areas. Methods the finite element analysis model of a long-span arch bridge was established. The near-field seismic action was selected in PEER database and applied to the arch bridge, and the peak value of time-history response was obtained. The average value of response peak value of 7 groups of waves in the current code is compared with the maximum value of calculated results when three groups of waves are combined and the average value of response peak value of 7 groups of near-field and far-field earthquakes. Results the minimum internal force responses of arch roof vertical displacement, arch roof axial force, arch foot bending moment and span suspender calculated by three groups of near-field seismic wave combination are 0.42 times and 0.48 times of those of 7 groups of near-field seismic wave, respectively, and the minimum internal force response of arch foot bending moment and span suspender is 0.42 times and 0.48 times of that of 7 groups of near-field seismic wave, respectively. 0.79 times, 0.75 times; The maximum values of the four responses calculated by three groups of near-field seismic wave combinations are 2.7 times, 2.8 times and 1.9 times higher than those of 7 groups of near-field seismic waves, respectively. The average values of the four response peaks obtained by near-field seismic waves in group 7 are 0.82 times, 0.85 times, 0.61 times and 0.61 times as much as those of far-field earthquakes, respectively. Conclusion for the long-span arch bridge of type III site, when three groups of near-field seismic waves are used to calculate the response according to the code, there is a great difference between the maximum value of the seismic response results of the three groups and the average value of the calculated results of the seven groups of seismic waves. The dispersion is very large; When seven groups of seismic waves are used to calculate the time-history response, the average value of the peak value of near-field seismic response is less than that of far-field.
【作者单位】：沈阳建筑大学土木工程学院;
【基金】：国家自然科学基金项目(51308348)
【分类号】：U441.3

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