远场大震对深厚覆盖土层地基上超高层建筑物的影响分析  

Influence and analysis of super-rise building on soil layer with deep deposit subjected to strong far-field ground motion

作　　者：陶磊[1] 张俊发[2] 

机构地区：[1]西安理工大学水利水电学院,陕西西安710048 [2]西安理工大学土木建筑工程学院,陕西西安710048

出　　处：《西安理工大学学报》2014年第1期79-84,共6页Journal of Xi'an University of Technology

基　　金：国家自然科学基金资助项目(51279162)

摘　　要：建造在深厚覆盖土层上的超高层建筑往往受到远场大震的影响较大。为了探讨这一现象产生的原因,从远场地震记录特征及超高层建筑自身的动力特性进行了分析。通过汶川地震时西安远场记录,结合西安地区的地质构造情况,分析远场地震动特征,并对一幢超高层建筑进行远场地震反应分析,研究远场大震对这类长周期建筑物的影响。通过对地震记录的频谱分析可知:①远场地震具有相对较小的加速度峰值、超长的持时以及丰富的长周期成分;②远场地震动的卓越频率小于El Centro记录,远场地震动优势频率段远小于El Centro记录。通过时程分析可知:在地震动峰值相似的情况下,远场地震对超高层建筑的动力响应远大于El Centro记录。深厚覆盖土层上超高层建筑自振周期较长,易与远场大震的长周期成分接近而发生共振,其响应与一般地震不同,进行抗震设计时,应对遭遇远场地震的情况予以重视。Major influence for super-rise building constructed on soil layer with deep deposit is subjected to strong far-field ground motion.In order to probe into this phenomenon,an analysis from far-field motion characteristic and dynamic characteristics of super-rise building is made.Based on far-field records and area of geological structure in Xi＇ an when Wenchuan earthquake took place,far-field earthquake motion characteristics are analyzed,and a far-field seismic response simulation analysis for a super high-rise building in Xi＇an is made to study influence of farfield earthquake to such long-period structures.Through the result of spectral analysis and response spectrum analysis,it indicates that firstly,far-field ground motion is of relatively lower peak ground acceleration,super long time of duration and abundant long period component; secondly,predominant frequency of far-field ground motion is smaller than El Centro,meanwhile,the dominant frequency range of far-field is much smaller than El Centro.From time history analysis,it indicates that in the similar of PGA condition,the dynamic response of super-rise building of far-field ground motion is greater than El Centro earthquake record.Vibration period of superrise building constructed on soil layer with deep deposit is long,and easy to close the long period component of far-field ground motion records to cause resonance,whose response is different from general seismic records.Accordingly,when a seismic design starts,more attention should be paid to the structure subjected to far-field ground motion.

关 键 词：远场大震 超高层建筑物 地震反应分析 深厚覆盖土层 

分 类 号：P315.1[天文地球—地震学] TU973.17[天文地球—固体地球物理学]