天然地震波强度及频率非平稳特征的影响因素  

STUDY ON THE FACTORS OF INTENSITY AND FREQUENCY NONSTATIONARY CHARACTERISTICS OF NATURAL SEISMIC WAVE

作　　者：杨开来 殷翔[1] 晁增辉 白永祯 韩旭 YANG Kailai;YIN Xiang;CHAO Zenghui;BAI Yongzhen;HAN Xu(Qinghai Earthquake Agency,Xining 810001,China)

机构地区：[1]青海省地震局,青海西宁810001

出　　处：《高原地震》2021年第1期35-41,共7页Plateau Earthquake Research

摘　　要：天然地震波或人工地震波是抗震设计的地震动输入,其强度及频率非平稳特征对于提升抗震设计结果合理性具有重要意义。利用相位差谱和三角级数公式推导了相位导数的计算公式,并将其带回三角级数,分析强度及频率非平稳特征的影响因素。研究发现,天然地震波强度及频率非平稳特征的影响因素包含三个,分别是相位导数的频率分布特征,幅值谱的变化规律,相位导数与幅值谱之间的频率对应关系。计算实例表明,相位导数的频率分布特征与加速度时程包线形状相符,而相位导数与幅值谱之间的频率对应关系同样具有规律,例如,强震段范围内的大幅值分布集中,而起始段和尾部段的小幅值分布集中。Natural seismic wave and artificial seismic wave are the input data of seismic design,and their non-stationary characteristics of strength and frequency are significant for improving the rationality of seismic design results.At present,scholars only focus on phase spectrum and amplitude spectrum,but ignore other factors.In this paper,the phase derivative is derived by using the formula of phase difference spectrum and trigonometric series,and it is taken back to trigonometric series to analyze the influencing factors of non-stationary characteristics of intensity and frequency.It is found that there are three factors affecting the strength and frequency non-stationary characteristics of natural seismic waves,which are the frequency distribution characteristics of phase derivative,the variation law of amplitude spectrum,and the frequency corresponding relationship between phase derivative and amplitude spectrum.The calculation example shows that the frequency distribution characteristics of phase derivative are consistent with the shape of acceleration time history envelope,and the frequency corresponding relationship between phase derivative and amplitude spectrum is also regular.The calculation example shows that the frequency distribution characteristics of phase derivative are consistent with the shape of acceleration time history envelope,and the frequency correspondence between phase derivative and amplitude spectrum is also regular.For example,the large amplitude distribution is concentrated in the range of strong earthquake segment,while the small amplitude distribution is concentrated in the starting and tail segments.

关 键 词：相位差谱 相位导数 幅值谱 频率非平稳特征 天然地震波 

分 类 号：P315.31[天文地球—地震学]