考虑行波效应的拱坝地震动力响应分析

Seismic response of arch dam considering traveling wave effect

为探讨地震波的行波效应在动力响应中的影响,以五嘎冲拱坝为实例,采用三维有限元分析方法进行地震动力时程分析.将考虑行波效应的模型与不考虑行波效应的地震均匀输入模型计算结果进行对比,分析在地震作用下大坝的加速度、动位移、动应力时程分布规律,总结出了一些拱坝在考虑行波效应后的动力响应规律.结果表明:相位差对坝体加速度影响显著,行波输入和均匀输入的加速度频率成分差别较大;相位差起着减小拱坝坝体动力响应的作用,大多数情况下,行波波速越小减小得越多;不考虑相位差对拱坝的结构设计是偏安全的.

To explore the influence of earthquake wave＇s traveling wave effect on the dynamic response, we carried out time-history analysis for the seismic dynamics of Wugachong arch dam using 3-D finite element model. Compared the results of considering traveling wave effect or not, the regularity distribution of dy- namic acceleration, dynamic displacement and dynamic stress response of arch dam during earthquake have been summed up considering the traveling wave effect. Phase difference has significant influence on the ac- celeration; there are large difference on components of acceleration frequency between traveling wave input and uniform input. Phase difference plays a role to reduce the dynamic response of arch dam. In most ca- ses, the smaller the velocity is , the more dynamic response reduces. Without considering the phase differ- ence in structure design of arch dam is safer.