俯冲带板内地震竖向加速度谱阻尼修正系数模型研究  

A damping modification factor model for vertical acceleration spectrum from slab earthquakes in subduction zone

作　　者：陈心锋 姜妍旭 刘名吉 Chen Xinfeng;Jiang Yanxu;Liu Mingji(School of Civil Engineering,Shandong Jianzhu University,Ji’nan 250000,China)

机构地区：[1]山东建筑大学土木工程学院,中国济南250000

出　　处：《地震学报》2022年第2期339-355,共17页Acta Seismologica Sinica

基　　金：国家自然科学基金(51878396)资助.

摘　　要：基于日本K-NET和KiK-net台网的4695条俯冲带板内地震记录,采用最小二乘法对阻尼修正系数(DMF)的几何均值进行关于阻尼比和谱周期的回归拟合,分场地类别建立了考虑阻尼比和谱周期的竖向加速度谱DMF模型。为探究震源、路径和场地效应对该模型残差分布的影响,采用随机效应模型将残差分离得到各类残差及相应的残差标准差,在此基础上进行DMF模型残差分析。研究结果表明,DMF可以采用阻尼比对数值的三次多项式、周期对数值的四次多项式来模拟。由于规范设计反应谱并非针对某一特定地震,规范提出的DMF模型并不包含震源和路径参数,但事件间和事件内残差关于矩震级、断层距离和断层深度的分布表明,在给定地震事件下,包含地震动参数的DMF模型将会改善模型的预测能力。In this study,4695 strong-motion records from subduction slab earthquakes in Japan obtained by the K-NET and KiK-net networks were used to develop a damping modification factor(DMF)model for the vertical acceleration spectrum.The DMF model considering the damping ratio and spectral period is established for four site classes,and the geometric mean values for DMF are used to perform regression fitting in respect to the damping ratio and spectral period by least squares method.To evaluate the influence of hypocenter,path,and site effects on the residual distribution of the model,the total model residuals and standard deviations were separated into between-event and within-event parts,and the within-event residuals were further divided into the between-site and within-site parts by using a random effects model.The results show that the effect of damping ratios on DMF can be modelled by the third-order polynomial of the logarithm of the damping ratios,a fourth-order polynomial of the loga-rithm of spectral periods can be used to model the effect of spectral periods for the DMF.The effects of source and path parameters were not modelled in this study because of DMF model is used to scale a design spectrum not associated with a given scenario earthquake.The distribu-tion of the between-and within-event residual distributions with respect to moment magnitude,fault depth and source distance suggests that including these terms would improve prediction capability of the model when a DMF is designed for scaling a 5%acceleration spectrum associ-ated with a scenario event for a give magnitude and source distance.

关 键 词：阻尼修正系数 竖向加速度反应谱 随机效应模型 俯冲带板内地震 残差分析 

分 类 号：P315.9[天文地球—地震学]