苏通桥非致地震反应及讨论.docVIP

苏通桥对非一致地震地面运动的反应和人工波质量的讨论 秦 权a，孙晓燕a，贺 瑞a，丁志峰b，温国樑c a－清华大学土木系，北京100084， b－中国地震局地球物理所，北京100081， c－台湾中央大学地球科学系，台湾中坜320-54 摘要：台湾集集地震SMART-II密集台阵的，带有GPS国际标准时间校准的7群非一致地震地面加速度记录，和2群以杂交法针对苏通桥桥位断层和地质构造产生的非一致地震人工地面加速度时程历史作为输入，分析了世界最大跨斜拉桥——苏通桥——对非一致地震地面运动的变形和内力反应。每群地震输入由两个或三个台站的三分量加速度记录组成。还考虑顺桥向与波传播方向、断层走向间不同夹角、大桥是否跨越断层的情况下非一致地震地面运动的反应，并与由每群台站记录中含最大水平地面峰值加速度的记录构成的一致地震地面运动的反应做了比较。比较表明：尽管相应的一致地震输入是由一群台站记录中含最大水平地面峰值加速度的记录组成，苏通桥的半数非一致地震反应仍比相应的一致地震反应大，个别情况的非一致反应甚至比一致反应大得多。因此，苏通桥这样的特大桥的抗震设计应当考虑非一致地震的影响。还提出桥梁设计者应根据桥的动力特性对地震安全性评价提出所需的地震动参数。还检查了有关部门对苏通桥抗震设计提供的人工加速度波的反应谱和互相关系数，结果表明桥梁设计者应当在多方面检查所提供的人工波的质量。 关键词： 非一致地震地面运动；场地效应；失相干效应；波传播效应；密集台阵；斜拉桥 中图分类号：U442.5+5, 文献标识码：A Responses of Sutong Cable-Stayed Bridge to Asynchronous Earthquake Ground Motions and Quality of Synthetic Time Histories Qin Q. a, Sun X.-Y. a, He Rui a, Ding Z.-F. b and Wen K.-L.c a-Tsinghua University, Beijing 100084, b-Geophisical Research Institute, China Seismology Bureau, Beijing 100081, c-National Central University, Chung Li, Taiwan 320-54 Abstract: 7 groups of asynchronous ground acceleration time histories of Chichi earthquake, Taiwan, Sept. 21, 1999, recorded by a dense closely spaced array SMART-II with GPS international standard time calibration, and 2 groups of synthetic asynchronous acceleration time histories generated by using a hybrid method of mode superposition and finite difference are used as earthquake ground motion inputs, to analyze earthquake responses of Sutong cable-stayed bridge with the longest span in the world. Different angles between the longitudinal direction of the bridge and wave traveling directions or direction of Chelonpu fault and cases of fault-crossing or fault-no-crossing of the bridge are considered. Its responses are compared with those to related synchronous seismic ground motions consisting of these with the largest peak ground acceleration in each group of inputs. The results show that responses of such a long-span bridge to asynchronous seismic ground m