基于强震动观测记录的新疆南天山地区地震动特性统计分析  

STATISTICAL ANALYSIS OF GROUND MOTION CHARACTERISTICS IN XINJIANG SOUTH TIANSHAN AREA BASED ON STRONG MOTION RECORDS

作　　者：阿布都瓦里斯·阿布都瓦衣提 唐丽华[1] Abuduwalisi Abuduwayiti;TANG Li-hua(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)

机构地区：[1]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《内陆地震》2021年第1期48-59,共12页Inland Earthquake

基　　金：地震科技星火项目(XH19051).

摘　　要：将布置在南天山地区的71个强震动台站从2007~2018年记录到的732组强震动加速度记录按照不同震级、震中距和场地类别分组,对加速度水平向分量和垂直向分量的加速度峰值(PGA)和放大倍数谱(β谱)及其特征周期(T_(s))和持时进行了统计分析。结果表明:(1)三分量PGA随震中距的变化规律符合已有的衰减关系。地震波的传播规律和特殊的地壳构造会影响同类震级和场地条件下的PGA大小。场地条件对水平向不同分量的PGA的影响有不同的特点或规律;(2)地震动垂直向分量T_(s)总体上小于水平向分量T_(s)。随场地依次变软,水平向分量T_(s)逐渐增大;而垂直向分量T_(s)随场地类别的变化规律不明显。随震级和震中距的增大,T_(s)有逐渐增大的趋势;(3)场地类别对地震动水平向分量的持时有一定的影响,随着场地依次变软,持时会有些增大,对于垂直向分量,则没有明显的规律。732 strong ground motion acceleration records from 2007 to 2018 recorded by 71 strong ground motion stations set in South Tianshan area were grouped according to different magnitudes,epicentral distances and site classifications,also,statistical analyses were carried out with duration,peak ground acceleration(PGA),amplification spectrum(βspectrum)and its site period(T_(s))for the horizontal and vertical components of the accelerations.The results show that:(1)Three-component PGA’s variation laws with the epicentral distances are consistent with the existing attenuation relationship.The propagation law of seismic waves and the special crustal structure will affect PGA values in the circumstances of same type of magnitudes and site conditions.The site conditions have different characteristics or laws for the influence of PGA on different horizontal components.(2)The vertical component ofβspectrum of T_(s)ground motion is generally smaller than the horizontal component.As the site becomes softer,the horizontal componentβspectrum T_(s)increases gradually;while the vertical componentβspectrum T_(s)does not change significantly with the site classification.As the magnitude and epicentral distance increase,βspectrum T_(s)has gradually increased.(3)the site classification has a certain influence on the horizontal component of the ground motion.As the site becomes softer,the duration will increase somewhat.For the vertical component,there is no obvious law.

关 键 词：场地类别 地震动加速度峰值(PGA) 放大倍数谱(β谱) 特征周期(T_(s)) 持时 

分 类 号：P315.9[天文地球—地震学]