远场长周期地震动频谱特征周期与强度指标研究  

Characteristic periods and intensity indexes for far-field long-period ground motion frequency spectra

作　　者：王博 刘伯权[1] 吴涛[1] 代慧娟[2] WANG Bo;LIU Boquan;WU Tao;DAI Huijuan(College of Civil Engineering,Chang’an University,Xi’an 710061,China;College of Architecture and Civil Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]长安大学建筑工程学院,西安710061 [2]西安科技大学建筑与土木工程学院,西安710054

出　　处：《振动与冲击》2018年第7期211-219,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51708037;51578077);中国博士后科学基金面上资助(2017M610616);陕西省博士后科研资助(2017BSHEDZZ111);中央高校基本科研业务费创新团队项目(310828173401)

摘　　要：目前尚未有针对远场长周期地震动的频谱特征周期表征参数与抗震分析用强度指标。选择40条远场长周期地震动,采用MATLAB编制程序,分别计算对应于每条地震动的12种代表性频谱特征周期参数与20种强度指标。基于远场长周期地震动频谱特征周期的平均值及变异系数计算结果,分析各周期参数的特性,并通过计算远场长周期地震动的20种强度指标与以周期和延性系数为变化参数的400个弹塑性单自由度体系5种最大地震响应(最大加速度、最大速度、最大位移、最大输入能、最大滞回耗能)间的相关系数,分析各强度指标与地震响应间的相关性。结果表明:不同周期参数所反映的地震动频谱特性不同,稳定性亦存在较大差异,分析建议以Hilbert边际谱平均周期Tmh作为远场长周期地震动的频谱特征周期表征参数;远场长周期地震动强度指标与最大地震响应的相关性和强度指标的类型、自振周期以及延性系数均有关系,其中,PGV与PGD在各周期范围内均与最大地震响应具有较好的相关性,且相关性随自振周期的增大而增强,建议作为远场长周期地震动抗震分析用强度指标。At present,there are no characterization parameters of characteristic period and intensity indexes of aseismic analysis for far-field long-period ground motion frequency spectra.Here,40 far-field long-period ground motions were selected,and 12 types of representative frequency spectra’characteristic period parameters and 20 types of intensity indexes for each ground motion were calculated using codes programmed with MATLAB.The characteristics of period parameters were analyzed based on the average value and variant coefficient’calculation results of long-period ground motion frequency spectra’characteristic periods.Besides,the correlations between intensity indexes and earthquake responses of far-field long-period ground motions were analyzed through calculating correlation coefficients between 20 types of intensity indexes and 5 types of maximum seismic responses including max acceleration,max velocity,max displacement,max input energy and max hysteretic dissipation energy of 400 single-DOF systems with two varying parameters of natural period and ductility factor.The study results showed that different period parameters reflect different frequency spectral characteristics,and their stabilities also have larger differences;Hilbert marginal spectral average period Tmh is suggested as the characterization parameter of characteristic period for far-field long-period ground motions;correlations between intensity indexes and maximum seismic responses are related to types of intensity indexes,natural periods and ductility factors;peak ground velocity PGV and peak ground displacement PGD have better correlations with maximum seismic responses under different natural periods,correlations grow with increase in natural period;so PGV and PGD are suggested as aseismic analysis intensity indexes for far-field long-period ground motions.

关 键 词：长周期地震动 特征周期 强度指标 单自由度体系 相关性分析 

分 类 号：P315.9[天文地球—地震学]