本研究利用台北盆地43個TSMIP強震測站之大量地震觀測資料進行單站頻譜比分析比較，探討地震震源深淺、震源遠近及震源方位角的改變對台北盆地之單站頻譜比(以下簡稱HVR)的影響。經由S波視窗及S尾波視窗的HVR結果比較顯示，地震震源深淺對於台北盆地之HVR，在0.2~3.0Hz頻帶有顯著的差異存在。其中深源地震之HVR高於淺源地震；震央距離對於HVR則無顯著差異；而震源來自西南方的地震普遍比東南方地震有較高HVR，且只影響盆地北邊邊緣北投及信義區一帶之測站，與盆地之三維構造或沖積層厚度分布有一定程度關聯性。二維及三維震波模擬結果指出，震波從不同方位及角度入射盆地之HVR會有所變化，震波從南邊進入盆地較東邊進入盆地具有較高HVR，而震波以大角度(65°)入射盆地比小角度(30°)入射盆地具有較高HVR，這與觀測資料HVR分析結果吻合。甲仙地震震波在嘉南平原台南區域激發出顯著的表面波現象，周期約2秒至4秒。本研究以二維及三維有限差分震波模擬，重現甲仙地震震波由山麓帶進入沖積層低速地層後快速產生表面波之現象，且發現震波由於淺部地層構造速度差異，在新市至善化附近區域沿著曾文溪一帶具有顯著的震波能量集中現象。而震波能量集中現象所形成的波形振幅放大及局部場址震波放大效應，造成TN110列車所處位置相較TN105列車位置具有較大之PGV及PGD值，可能是造成高鐵TN110列車脫軌的原因。 The earthquakes were well recorded by very dense strong-motion network Taiwan Strong Motion Instrumentation Program (TSMIP). The sufficient records provide an opportunity to analyze the earthquake position how influence the basin response. We apply single spectral ratio method (H/V ratio) to analyze the records at 43 stations of the Taipei TSMIP network. The result of H/V ratios comparison of depth indicated the H/V ratios obtained using deep events for the most part larger than shallow events at low frequency (0.2~3.0Hz). The analysis result of H/V ratios comparison of azimuth indicate that the H/V ratios obtained using southwest earthquakes generally larger than southeast when the stations located in the northern part of the basin, but show unapparent when the stations near the central and southern part of the basin. The result of H/V ratios comparison of epicenter distance indicated the H/V ratios show unapparent spectra ratios difference between far and near epicenter. We apply 2D and 3D numerical modeling to Taipei basin. The simulations show that for the Taipei basin, generation of large H/V spectral amplifications occur for large degree planar S-wave front. The simulations also show that the H/V spectral amplifications display strong planar S-wave front azimuthal dependence. The modeling obtained similar conclusion with the observed analysis. In this study we use 2D and 3D finite-difference method to simulating the wave propagation of the JiaSian earthquake. The results of the simulation demonstrate that the long duration surface wave of the west ChiaNan plain resulting from the multi-pathing waves trapped in the top Pleistocene formation. The snapshots of the wave propagation display that the seismic wave bending on the Shanhua and Shinshi area along Zengwun River. The larger PGV and PGD maybe the reason explains that the TN110 train de-railed but TN105 not cause by the seismic wave bending and local site effect.
