在台灣除盆地地形外，平原區域亦屬於沖積層，其放大特性亦值得關切。台灣西部地區的地震，雖然不及台灣東部地區頻繁，但多屬於淺部地震，且西部台灣為主要的人口匯集區，地震常會造成重大的傷亡及損失，可算是嚴重的天然災害。台灣中地區範圍涵蓋科學園區，且地震資源豐富，提供我們探討平原地區放大倍率之分佈，提供建立地震微分區之參考。本研究主要目的為建立區域之地震微分區，因此除區域性之場址放大倍率分佈外，地表下之場址之主要放大頻率分佈亦為一參考依據，藉由涂嘉勝（2005）以微地動探討台中地區之主頻分佈將成為本研究之重要參考，以建立台灣中部地區之地震微分區。 ; The improvement of structural seismic design, which needs a proper definition of seismic demands for different site conditions, can efficiently prevent the damage of structures from the earthquake excitations and is the best way for earthquake hazard mitigation. The Central Weather Bureau has installed a very dense ground-motion array in Taipei basin. We used these earthquake data collected in the last decades to investigate the local site effects and its influence in the ground shaking for the Central Taiwan.Based on the attenuation relationship, which was modified by the records of reference sites to eliminate the source and path effects by events, the site effects of each TSMIP station in the study area were discussed in terms of an amplification factor to the reference sites (hard sites). Both the PGA and the spectral acceleration were studied in this paper. The ground motion amplification factors that incorporate more detailed information on site conditions can be used to remove bias and reduce the uncertainly of ground motion estimates from the attenuation relationship. All results will be provided for microzonation of site effect and improve the methodology for a better earthquake hazard mitigation purpose. Key Words: Site Effect , Microzonation ,Site condition ; 研究期間 9701 ~ 9712
