不同谱拟合方法对场地地震反应的影响研究

Research of effect of different modification methods on seismic geotechnicai analyses

在结构的抗震分析中.为使地震波的加速度反应谱能够与目标谱拟合,提出了不同的谱拟合方法。由于场地条件影响结构场地的危险性分析及结构反应分析,因本文旨在研究不同谱拟合方法对场地地震响应的形响。根据某实际场地的目标反应谱选择14条实测地震波,对时城修正方法和频域修正方法对场地地震反应的影响进行了评估,且选择了循环应力比率和场地放大系数以及有限滑动位移等参数来表征场地的地震反应。研究表明,使用时域修正方法与频域方法会使循环应力比率比放缩方法略微减少,而场地放大系数基本一致。对于有限滑动位移而言,在较浅的土层,放缩法所得到的有限滑动位移略大,而对于较浅的土层,则得到位移较小。

In the seismil analysis of structures,typically recorded,ground motion and to match its acceleration response spectrum to the target response spectrum.Because of the influence of site conditions structural field of risk analysis and structural response analysis,the purpose of this paper is to study the impact of different modification techniques on results of seismic geotechnical analyse.Fourteen motions were selected according to an actual site,and scaled and also modified using both time domain（td） and frequency domain（fd） techniques.It is shown that cyclic stress ratios and amplification factors are similar for all sets of motions.Smaller Newmurk-type slope displacements were observed for the modified motions for a shallow sliding mass,but larger Newmark-type slope displacements were observed for the modified motions for a deep sliding mass