摘要
一般认为断层有一定的隔震作用 ,但是也有不少震害表明断层附近的破坏反而比较严重。为探讨其中机理 ,采用有限元方法分别建立包含不同倾角无厚度断层的场地模型 ,并分析了在各种频率入射波的作用下该场地的动力反应。计算结果表明 ,断层对场地的动力反应有一定的放大作用 ,特别是当入射波的频率与场地的基频接近时 ,放大效应更为明显。计算结果还表明 ,断层的倾角对场地的动力反应也有影响 ,随着断层倾角的减小 ,断层出露点附近的动力放大效应增大。
It is believed that fault will absorb some energy from the seismic waves through it. But many examples of seismic disaster show that relatively greater damage occurs beside the surface fault than the other places. To explain the reason of such a phenomenon, Finite Element Method is used in this paper to build some ground models containing faults with various rake angles, and the responses of the models' surfaces under the incident waves with different frequencies are analyzed. The results indicate that amplification of ground motion is observed where the fault exists, especially when the frequency of the incident wave approximates to the site natural frequency. Besides, the angle of the fault is in response to the ground motion: the smaller the angle, the larger the amplification in the site where the surface fault exists.
出处
《地震研究》
CSCD
北大核心
2004年第3期283-286,共4页
Journal of Seismological Research
关键词
断层
动力反应
动接触
有限元
fault, dynamic response, dynamic contact, finite element
