利用微振儀單站水平／垂直頻譜比形探討地盤特性之研究：以臺南都會區為例

INVESTIGATING THE GROUND CHARACTERISTICS USING HVSR CURVES WITH MICROTREMOR MEASUREMENTS: THE URBAN AREA IN TAINAN

李振毓(Chen-Yu Li) ； 吳建宏(Jian-Hong Wu) ； 李德河(Der-Her Lee) ； 陳冠宇(Kuan-Yu Chen)

《中國土木水利工程學刊》 33卷2期 (2021/04) Pp. 125-137

https://doi.org/10.6652/JoCICHE.202104_33(2).0005

摘要

本研究搭配臺南都會區內中級土壤液化潛勢地圖（比例尺：1／2500）在調查的622孔地質鑽孔資料進行單站式微振動量測，探討微振動量測結果在短期多次量測及長期量測上的一致性，以及確認臺南都會區地盤卓越頻率集中在1.0 ～ 2.0 Hz，以及卓越頻率在空間上的分布與地盤地工特性分區之關係。另外藉由與鑽探所得地層資料與標準貫入N值的垂直分布，進行水平／垂直頻譜比形的分類及確認其高頻率區與現地岩盤上方沖積層特性的對應性。藉由本研究微振量測搭配中級土壤液化潛勢地圖調查鑽孔的研究，將有助於回應國內瞭解地盤動態特性與補充地震防災上的需求。

關鍵字

微振儀 ； 單站法 ； 頻譜比 ； 標準貫入N值

並列摘要

This study conducted 622 single-station microtremor measurements near the boreholes, which were used to generate the hazard map of the soil liquefaction with scale of 1/2500 in Tainan urban area. This study confirmed the consistency of HVSR curves with many measurements within a short time and the long-term periodic measurements. The predominant frequency of the lands in the Tainan urban area is concentrated between 1.0 and 2.0 Hz. The geotechnical properties in each geotechnical zone govern the spatial distribution of the predominant frequency. In addition, we classified the horizontal to vertical spectrum ratio (HVSR) waves as 11 waveforms, and confirmed that the high frequency parts of the HVSR curves, which are higher than the predominant frequency, correlate to the sediment deposit pattern and the depth of the soft soils in the boreholes. This study helps the engineers realize the site effect and highlight the importance of integrating microtremor measurements associating with the high-density borehole data in the seismic disaster mitigations.

並列關鍵字

microtremor ； single station ； spectrum ratio ； SPT-N