Summary: | 碩士 === 國立中央大學 === 地球物理研究所 === 94 === We used microtremor measurement to investigate the site effect in Taipei basin region by applying single spectral ratio method (Nakamura, 1989), the analyses of site effect can be taken as reference for the seismic resistance design and reducing damage from earthquake. After that, we calculated the Kg value of each site, then we can rapidly and easily obtained the local liquefaction vulnerability index.
In this study, we performed measurement on 589 points respectively, and analyzed the site effects. The dominant frequency of site effect in the Taipei basin is very close relation to the sungshan formation.
The distribution of the dominant frequencies shows that the areas near the basin edge have a higher dominant frequency. It is about 2.0~6.0Hz near the basin edge in the north, east and south. The western part of the Taipei basin, Sungshan area and Banciao area show a low dominant frequency in the contour map, it is about 0.8~2.0Hz.
We also calculated the “Kg value” (Nakamura, 1996) for estimating the earthquake damage of ground liquefaction area. In this study, Kg value is greater than 80, it had good correlation to compare with drilling.
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