在地質構造複雜的台灣，各類場址對於地震之放大效應影響極大。台灣南部地區，雖然不及台灣東部地區頻繁，但多屬於淺部地震。2006年1226恆春地震，雖屬於深層地震，但對於恆春地區之地震動大小亦造成房屋倒塌。從地形與地面地質的特性初步研判，屏東平原係一構造陷落而成之地溝狀平原，由其東側潮州斷層崖下之河川沖積扇以及北側荖濃溪、楠梓仙溪等河川沖積作用而形成。在地形的變化上，值得我們進行探討，其地震對於屏東地區場址特性之影響。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，藉由江賢仁（2005）及古美玲（2001）以微地動探討屏東地區之主頻分佈將成為本研究微分區之重要參考，以建立台灣屏東地區之場址放大係數與土層係數之關係。 ; 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. ; 研究期間 9801 ~ 9812
