| Abstrakt: |
To help understand the ground motions of the topographic site, the workers of Seismic Bureau of Gansu province deployed a temporary array of seismometers around the Wenxian hill and recorded ground motions from Wenchuan aftershocks. Only 11 aftershocks were recorded on all stations across the hill, these data were collected to facilitate studies of site response, wave propagation effect, and correlations of mainshock damage with local site conditions. In this paper, we analyze the weak motion data as well as the strong-motion data, and conduct comparisons of peak ground accelerations, seismic spectra analysis, and spectral ratio analysis. A more complete description of the site’s amplification, its relationship to topography, and its relationship to earthquake source effects are provided. The result shows that the ground motion was consistently amplified at station at or near the top of the hill compared with stations at the base of the hill and the amplifications frequency dependent and has its maximum at the resonant frequency of the site. |
