【作者】 董娣；

【导师】 周锡元； 闫维明；

【作者基本信息】 北京工业大学 ， 结构工程， 2006， 博士

【摘要】 本文利用欧洲强震数据库、美国强震数据库以及我国台湾地区的上万条地震记录,并根据研究内容不同,按照震级、震中距、场地类别或者震源机制进行了分组,在分组记录的基础上,从不同角度对地震动若干特性进行了比较详细的统计分析。除此之外,本文还研究了场地类别、传播途径和震源机制等因素对地震动若干特性的影响,着重分析对比了同样震级、距离和场地条件下记录到的地面运动的差异和不确定性影响,初步分析了可能产生这种不确定性的原因。本文在欧洲强震记录数据库中挑选出163组强震记录,分析了地震动强度包络函数的统计特性,着重讨论了地震动正负向包络线是否具有对称性以及三分量包络线的异同。结果表明,平均包线基本上都可以用单峰点的曲线来表示,但是正负向包络线一般都不具有对称性,其光滑程度也不尽相同。从三分量包络线的比较中可以看到,竖向分量的平均包络线的峰值最早出现,攀升速度也较快;与竖向分量包络线相比,水平分量的平均包络线显得更宽平一些。论文以美国西部、日本神户、土耳其、墨西哥、台湾集集地震等基岩场地上的156组强震记录为基础,应用强震记录的穿零率来反映频率特性随时间变化的非平稳特性,并与采用峰点法考虑涟波效应的结果进行了比较。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。考虑到地震动主频(卓越频率)对结构反应具有控制作用,文章对强震记录主频的时变特性也进行了初步的研究,与穿零率比较,主频随时间的的波动变化显得更大一些。论文还针对921台湾集集地震中不同震中距和不同类别场地上的地震记录,研究了场地类别对地震动持时、PGA、包络线、反应谱等的影响。结果表明地震动水平分量的持时随着场地依次变软而增大;断层方向对PGA衰减特征有一定影响;不同震中距离和场地条件下加速度时间历程的包线基本上都是单峰点的时间函数;地震动加速度水平分量包络线与竖向分量包络线有明显的不同;在震中距相同的条件下,场地愈软弱,在短周期段的谱比值EW/NS愈接近1。一般来讲场地愈软,在短周期(<0.1秒)段的V/H谱比值有变大的趋势,而在长周期(>特征周期)段则是变小的趋势;而且相对来说V/EW谱比值随场地变软而减小的趋势更明显一些。文中将欧洲及其周围地区的强震记录按照震源机制分组,详细的分析了不同震源机制对地震动近断层频谱特性的影响,结果表明震源机制对地震动频谱特性的影响较为显著。逆断层地震动的卓越频率略大于具有其它类震源机制的地震动的卓越频率。不同震源机制的地震动相位差谱均值以及均方差随震中距不同有显著的差别。在反应谱的短周期段,走滑断层地震动反应谱比值最大;在长周期段,斜断层地震动反应谱比值最大;正断层地震动反应谱的比值在整个工程师感兴趣的频段内的变化相对来说都比较平缓。更多还原

【Abstract】 This thesis collected about ten thousand earthquake records, and the records aremainly from Euro databank, American databank and Taiwan’s network and some ofthem are from others country or regions. The records are sorted by magnitude,epicenter distance, site classification or fault mechanism as well according to theresearch objectives. Based on grouped data, detailed statistical analyses have beendone for strong ground motion characteristics from different aspects. In addition, thethesis also researches the effects of site classification and fault mechanism uponground motion characteristics. Finally, the thesis analyses the uncertainty of groundmotion and its effect factors.The thesis pick up 163 groups strong ground motion records from Euro databankand analyses its statistical features of amplitude envelope line. The symmetry of plusand minus direction envelope line and the difference among three-componentenvelope lines was emphasized and concerned. From the statistical results, it can beseen that the envelope line is asymmetrical, and the smoothness degree of theconfiguration of envelope line of plus and minus direction is different too. However,the envelope line can be represented by single peak curve commonly. About threecomponents envelope lines, the horizontal amplitude are all more than itscorresponding vertical component; the station of peak of vertical component is moreclose to y-axis, this means that climb speed of vertical component envelope line isfaster compared horizontal component; and that the shape of horizontal envelope lineis wider and flatter.Based on the 156 groups of earthquake bedrock recordings, those are mainly fromWestern US, China Taiwan and so on. The thesis mostly researches the crossing-zerorates of strong earthquake acceleration records, and uses them to reflect the frequencynon-stationary features. Furthermore, we utilize the time interval between neighboringpeak point to reflect the frequency non-stationarity incorporating the effect of ripplesand make comparisons with the corresponding results by using the crossing–zeromethod. The results of analyses and comparisons indicate that the crossing-zero ratescan reflect the frequency non-stationary features to certain length. It is noticed that thepredominant frequency has a role of control in structure response, the thesis alsoanalyze the time-variable characteristics of the predominant frequency, compared withthe crossing-zero rates, and find out that the fluctuating feature is more obvious inthis case.According to the epicenter distance and the site classification, the thesis sorts 404groups of earthquake recordings of the main shock, chi-chi earthquake China Taiwanin 1999. Based on these data, the statistic properties of duration, PGA, envelopes, andresponse spectra ratio of horizontal and vertical component of the accelerationrecordings have been studied. The duration of horizontal components of accelerationrecords increases as site condition becomes softening. The direction of fault slip has更多还原