Interaction of geometry and mechanical property of trapezoidal sedimentary basins with incident SH waves
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- 作者：Chuanbin Zhu ; David Thambiratnam
- 关键词：Basin ; Seismic response ; SH waves ; Surface waves
- 刊名：Bulletin of Earthquake Engineering
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：14
- 期：11
- 页码：2977-3002
- 全文大小：2,852 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Earth sciences
Geotechnical Engineering
Civil Engineering
Geophysics and Geodesy
Hydrogeology
Structural Geology - 出版者：Springer Netherlands
- ISSN：1573-1456
- 卷排序：14
文摘
This paper investigated the effects of basin geometry and material property on the response of 2D trapezoidal sediment-filled basin to incident plane SH waves. Ten basin configurations with different geometries were developed, and then their seismic responses to both Ricker wavelets and seismic records were simulated by using an explicit finite difference scheme. The definition of deep/shallow basin, the precondition for the observation of prominent surface waves and the influential area of edge effects of the shallow basin were discussed quantitatively in this study. The followings were concluded: in the common velocity contrast range (vs1/vs2 < 10), the fundamental frequency a basin with W/H > 3.0 can be estimated approximately by 1D theory. The complexity of peak ground acceleration distribution pattern, the width of the most affected section as well as the amplitude of ground motion in the Edge Region increase with incident frequency. Prominent surface waves can only be observed when the incident wavelength is shorter than the critical wavelength λc. The interaction between incident wave and basin dynamic property plays a dominant role on the peak ground acceleration amplitude while the interaction between incident wave and geometry plays a more significant role on the peak ground acceleration distribution. For very shallow basin, different areas along the basin width are affected to different extents. Only a limited area close to the basin edge is influenced significantly. It is more feasible to propose spectral aggravation factor for different surface zones respectively than a uniform constant as a tool to calibrate the 1D-based design spectrum so as to take the basin effects into account.