本研究計晝研究課題為地震境況模擬、損失評估與應變對策研究。並以淺層地下速度構造、路徑與地 盤效應分析作為本研究主要研究内容。對於地震危害度分析研究方面,建立強地動衰減模式是必要 的。合適的衰減模式可以表達區域強地動的衰減特性,並且可以用來預測一個特定區域的地動加速度 值,用於區域現地建築抗震設計方面。因此,我們要研究強地動地震資料對於在台灣西南部震波的衰 減關係。利用微地動陣列的垂直分量紀錄與水平分量紀錄可以求得表面波相速度,本研究使用各種方 法推求雷利波相速度與洛夫波相速度,並利用相速度頻散曲線逆推地下淺層速度構造。而本研究所使 用的方法有:SPAC法、CCA法、線性SPAC法利用垂直分量紀錄計算雷利波相速度;SPAC+L法、 SPAC-L法、CCA-L法利用水平分量紀錄計算洛夫波相速度。使用這些陣列法最大缺點在於必須有嚴 謹的陣列架構,在測量上容易受到限制,而線性排列的SPAC法可以改善這項缺點。每種方法的最大 差別在於可求得不同波長範圍的表面波相速度,本研究評估各種陣列法可分析的波長範圍與陣列半徑 的關係。本研究針對台灣西南部進行微地動陣列量測及高密度微地動測量,分別求得其淺層剪力波速 度構造及場址特性,建立一個包含淺部速度構造之完整三維速度模型,進行震波模擬。
A strong ground-motion attenuation equation is essential and influential for seismic hazard analysis. A suitable attenuation equation can express the characteristics of the strong ground-motion attenuation for a region, and can be used to predict the ground-motion value of a specific site for seismic resistance design. Therefore, we need to study the strong ground-motion attenuation relationship for earthquakes in SW Taiwan. Several techniques, such as the spatial autocorrelation (SPAC), the centerless cicular array (CCA), the spatial autocorrelation method along a linear array using vertical component data as well as the SPAC+L, SPAC-L and CCA-L methods using only horizontal component data, which are wildly applied in studying subsurface shear-wave velocity structures. The main purpose of this research is to use the above methods to obtain dispersion curves which are further used to infer the phase velocities of Rayleigh waves and Love waves recorded by a circular array deployed in SW Taiwan. Despite of the above, the other important task of this study is to investigate the resolution in different wavelengths for each method, which can play an important information for future study in deployment different sizes of array. The shallow S-wave velocity structures and site effect in SW Taiwan were respectively estimated by the microtremor array measurements and dense station measurements. The complete 3D velocity model was constructed with the shallow structures to simulate the seismic wave propagation in SW Taiwan