摘要
利用日本强震观测网KiK-Net中两个基岩台站、两个Ⅲ类场地台站中数百条强震记录,对比基岩场地和Ⅲ类场地的地震动特性,分析傅里叶谱卓越频率与震级和距离的关系,以及上覆岩土层对地震动的影响。分析结果表明:基岩场地上,地下和地表各分量傅里叶谱卓越频率随震级增大或距离增大而减小,大小及分布规律基本一致;Ⅲ类场地上,地下记录各分量傅里叶谱卓越频率随震级增大或距离增大而减小,而地表记录的这一规律则不明显,且地下、地表卓越频率大小及分布明显不同,对于同为Ⅲ类场地但土层条件不同的台站其变化也不同。说明坚硬的基岩场地对地震动影响较小,而基岩上覆土层对地震动有明显的影响且其影响具不确定性。
Several hundred strong motion records from two bedrock stations and two classⅢ stations from the KiK-Net in Japan were used to analyze ground motion features,the relationship between Fourier spectrum dominant frequency and magnitude or distance,and the effect of shallow surface rock and soil layers on ground motion.At the bedrock stations,both underground and at the surface,the Fourier spectrum dominant frequencies for three components decreased with increasing magnitude or distance,and exhibited similar values and distribution.However,at classⅢsites,only the underground sites displayed a decrease in their three-component Fourier spectrum dominant frequencies over increasing magnitudes or distances.At these classⅢ sites,the Fourier spectrum dominant frequencies displayed significantly different values and distributions between the underground and surface ground motions,and the changes are different between the ground motions at stations with different soil conditions.These results indicate that hard bedrock has little effect on ground motion;however,an overlying soil layer on the bedrock has a profound and uncertain effect on ground motion characteristics.
出处
《地震工程学报》
CSCD
北大核心
2015年第3期743-747,共5页
China Earthquake Engineering Journal
基金
国家重点基础研究发展(973)计划(2011CB013601)
国家自然科学基金重大研究计划集成项目(91215301)
环保公益性行业专项(201309056)
关键词
地震动
卓越频率
震级
距离
场地条件
ground motion
dominant frequency
magnitude
distance
site condition
