摘要
为了分析地震波斜入射下对场地地震的影响,基于显示动力有限元法,采用黏弹性人工边界,以SV波斜入射不同坡度凸起地形,分析了不同入射角下凸起场地震动放大系数和傅里叶谱变化情况。其验证模型解析解和数值解吻合较好。数值模拟结果表明:随着斜坡坡度的增大,地震动放大系数增大,其斜坡上放大系数变化明显。X向放大系数大于Y向放大系数。频率在0.2~1 Hz的傅里叶曲线随着凸起地形坡度增加而增大;30°入射EI-centro波时,在低频段随着入射角的增大,傅里叶谱幅值呈减小趋势,高频段监测点的傅里叶谱幅值随着入射角的增大而增大,在1~10 Hz高频段,幅值变化速率最大。
In order to analyze the impact of seismic waves on site earthquakes under oblique incidence of seismic waves,based on the explicit dynamic finite element method,the viscoelastic artificial boundary is used,and SV waves are obliquely incident on the convex terrain with different slopes,and the ground motion amplification of the convex site under different incidence angles is analyzed.Coefficient and Fourier spectrum changes.The analytical and numerical solutions of the verification model are in good agreement.The numerical simulation results show that with the increase of slope gradient,the amplification factor of ground motion increases,and the amplification factor on the slope changes obviously.The X-direction magnification factor is greater than the y-direction magnification factor.The Fourier curve with a frequency of 0.2~1 Hz increases with the increase of the slope of the convex terrain;when the EI-centro wave is incident at 30°,the amplitude of the Fourier spectrum decreases with the increase of the incident angle in the low frequency band.Small trend,the Fourier spectrum amplitude of the monitoring points in the high frequency band increases with the increase of the incident angle,and the amplitude change rate is the largest in the high frequency band of 1~10 Hz.
作者
孙帅锋
邵伟伟
曹明星
SUN Shuai-feng;SHAO Wei-wei;CAO Ming-xing(Northwest Research Institute Co.,Ltd of CREC,Lanzhou 730099,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《工程爆破》
CSCD
北大核心
2024年第1期44-52,共9页
Engineering Blasting
关键词
斜入射
有限元
黏弹性边界
放大系数
傅里叶谱
oblique shot
finite element
viscoelastic boundary
amplification factor
Fourier spectrum
