复连续小波变换实现地震波在任意时-频域随机相位的方法*

(1.招商局重庆交通科研设计院有限公司,重庆 400060; 2.东京大学新领域创成科学研究科,日本千叶县柏 277-8561)

抗震设计; 人工地震波; 小波变换; 地震动输入

Phase Randomization of Ground Motions with Arbitrary Time-frequency Range Using Complex Continuous Wavelets
XIE Haoyu1,HONDA Riki2,ZHENG Wanshan1

(1.CMCT Research & Design Institute Co.,LTD,Chongqing 400060,China)(2.Graduate School of Frontier Science,The University of Tokyo,Kashiwa 277-8561,Chiba,Japan)

seismic design; artificial ground motion; wavelet transform; input ground motion

备注

动力分析过程中输入地震波的选择非常重要,通过扰动自然波生成人工地震波是丰富设计地震波池的方法之一。提出使用复连续小波变换来修改、扰动自然波的方法来拟合人工地震波,以2000年日本鸟取MW6.7地震为研究对象,对比Shannon小波基和Gabor小波基在生成人工波过程中的特点。结果 表明:使用改进方法可以在任意指定的时-频域上修改地震波的相位谱从而产生人工波,且Shannon小波对地震波能量的保留优于Gabor小波,故 Shannon小波基是更好的选择。

For dynamic analysis,selection of input ground motions is of huge importance.The diversity of the set of input ground motions could be enhanced by simulating the artificial ground motions from natural earthquakes.A methodology utilizing complex continuous wavelets to simulate artificial ground motions areput forward,taking the 2000 Tottori earthquake(b>W6.7)as aresearch target,and the characteristics of the Shannon wavelet and the Gabor wavelet are compared in the article.The result shows that the new methodology could have time-frequency domain arbitrarily oriented,and the Shannon wavelet is the optimal choice as it could maintain the power better than the Gabor wavelet.