基于美国西部基岩强震加速度记录资料,采用多重滤波技术计算水平向和竖向地震加速度记录时程的时变功率谱值,并利用非线性最小二乘法拟合了对应于各条加速度记录时程的时变功率谱模型参数值。采用经验统计方法,分析了水平向和竖向加速度时变功率谱模型参数随震级、震中距及频率的变化规律,建立其衰减模型,并由多随机变量一致加权最小二乘法拟合得到了各衰减模型的系数值。通过与现有时变功率谱衰减规律的对比分析,证明了本文提出的衰减模型的合理性。
Based on the rock surface strong motion dataset in west America and Kameda's multifilter technique,the evolutionary power spectra of horizontal and vertical ground motion are calculated.The evolutionary power spectra parameters of every ground motion are achieved by the nonlinear least square method.The attenuation laws of the evolutionary power spectra parameters with earthquake magnitude,hypocentral distance and frequency are analyzed by experiential statistical method,and the attenuation models of the evolutionary power spectra parameters are developed.The coefficients of the attenuation models are also achieved by consistent weighted least square method for multi-random-variables.The rationality of these attenuation models are approved by compared with other's attenuation models.
