【摘要】 本文将美国西部、中国台湾和其它地区在基岩场地上的156组地震记录按不同震级、震中距分组,分析了持续时间随震级、震中距的变化规律,在此基础上研究了强震记录的穿零率以及主频的时变特性,并用一直线来拟合穿零率随时间的变化规律,给出了此直线拟合参数在不同震中距、记录方向条件下的取值范围,以此来反映频率特性随时间变化的非平稳性,此外还通过运用峰点法在频率特性非平稳性中考虑涟波效应。所得结果与穿零率的相应结果进行了对比。文中的分析结果表明,穿零率方法是可以在一定程度上反映频率特性的非平稳性的。更多还原

【Abstract】 According to the magnitude and the epicenter distance,this paper sorts 156 groups of earthquake bedrock recordings of the Western of US,Taiwan China,and other regions.Based on the data,we analyze the statistic features of duration along with the magnitude and epicenter distance,and study the time-variable characteristics of the crossing-zero rates and predominant frequency.We think that these can reflect the frequency non-stationary of strong ground motion.Then,we fit the crossing-zero-rate curve by a straight line,and give the fitting parameters of straight lines for different epicenter distance and different recording directions.In addition,we utilize the peak-point-interval method to analyze the frequency non-stationary to incorporate the effect of ripples and contrast the resulting with the corresponding resulting using the crossing zero method.The results of analyses and comparisons indicate that the crossing-zero rates can reflect the frequency non-stationary features to certain extent.更多还原