大跨拱桥在空间变化地震动下的响应

通过对ＳＭＡＲＴ－１台网一强震记录资料的统计分析，给出了与此次地震相应的地震劝空间相关模型及其参数。然后以四川宜宾金沙江江南门大桥为例，研究了地震动空间变化对大跨度拱桥抗震安全的重要意义。数值分析结果表明：地震动空间变化对主拱圈内力响应有重要影响，忽略这种变化将导致对拱内力的严重低估。对于大跨度柔性拱结构，拟静力和动力交叉响应项对总响应的贡献可以忽略不计，从而相应的结构随机响应计算方法得到简化。

Random Response of Long-Span Arch Bridge under Spatially Variable Seismic Excitations

In the present paper,a spatial coherence model of seismic ground motion is suggested and the model parameters are determinated by statistical analysis of acceleration records from SMART-l array.And then taking Nanmen arch bridge as an example f the importance of the spatial variation of seismic ground motion to long-span arch is investigated.The results show that the spatial variation of seismic ground motion affects seriously the internal force response of the arch structure.Ignoring the spatial variation will lead to substantial underestimation of the internal force of the arch.The contributions of the cross term between the quasi-static and dynamic response can be negligible for nexible arch structures f and then the computing method of strucutral response may be simpliffied in this case.