盆地场地远场长周期地震动输入的确定  

Determination of far-field long-period ground motion input in basin

作　　者：刘烁宇 李英民[1,2] 戴明辉 LIU Shuoyu;LI Yingmin;DAI Minghui(College of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technique for Construction of Cities in Mountain Area,Chongqing University,Chongqing400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《建筑结构学报》2018年第8期110-118,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51478068,51478067)

摘　　要：盆地场地的长周期结构在远场长周期地震动作用下震害明显,目前国内设计规范尚未将低幅值的远场长周期地震动记录纳入统计范围。研究盆地场地远场长周期地震动输入方法,可用于国内盆地建筑的抗震补充验算。文中针对日本沉积盆地台站地震动记录数据进行统计,拟合出盆地效应与沉积层厚度的关系曲线。结合国内板壳内地震下的基岩地震动衰减关系、盆地效应与沉积层厚度关系曲线以及局部工程场地放大作用,给出适用于国内的盆地场地远场长周期地震动输入方法。基于渭河盆地内的西安市区以及周边地震环境,进行了远场长周期地震动输入方法的案例分析。分析结果表明：盆地效应对加速度反应谱的放大作用和对地震波到达时刻的影响,均随盆地沉积层厚度的增加而变得更显著。文中方法综合考虑了震源分布、震级、震中距、盆地效应和局部工程场地的影响,可用于估计国内盆地场地远场长周期地震动加速度反应谱及其地震动时程,其模拟的加速度反应谱与地震动时程符合实际远场长周期地震动记录的特征。While seismic damages of long period structures subjected to far-field long-period ground motions were prominent in basin, far-field long-period ground motion records with low amplitudes were not included in current codes. To provide supplementary analysis for buildings in basins of China, the method of inputting far-field long-period ground motions in basin was studied. The ground motion record data of stations located in the sedimentary basins of Japan were summarized, and the relationship between the basin effect and the thickness of the sedimentary layer was provided via fitted curves. A method of determining far-field long-period ground motion input for buildings built in typical basins in China was proposed, which was based on the attenuation relationship of rock ground motion induced by intraplate earthquake in China, the relationship between the basin effect and the thickness of the sedimentary layer, and the amplification effect of local site. Then, a case analysis of far-field long-period ground motion input method was provided, which was based on the Xi＇ an in Weihe basin and surrounding seismic environment. The results indicate that as the thickness of sedimentary layer increases, the influence of basin effect on acceleration response spectrum amplification effect and arrival time of seismic wave is remarkable. The influences of source distribution, magnitude, epicentral distance, basin effect and local site were considered in the method. The method can be used to estimate the acceleration response spectrum and time history of far-field long-period ground motions in basin of China. Using the method, the predicted acceleration response spectrum and time history agree well with the actual features of far-field long-period ground motion records.

关 键 词：长周期结构 远场长周期地震动 沉积盆地 土层速度结构 加速度反应谱 人造波 

分 类 号：TU973.212[建筑科学—结构工程]