高層建築受到強風作用下的結構反應包括了平均位移與動態位移反應。其中動態位移反應除了結構的自然振動頻率特性之外，又含有大氣紊流造成的低頻特性。因此，以適用於較高頻範圍的加速度計配合適用於DC至極低頻的全球定位系統(GPS)才能取得完整的高樓受風反應行為。本文在一單軸振動平台裝設GPS與加速度計，分別以簡諧振動與白噪振動檢視GPS與加速度計之基本性能，藉以建構GPS訊號與加速度計訊號之合成方法，而後應用於一棟位於台北市之三十層樓高層建築的實場監測。由於目前商用GPS的解析度約為5mm，仍須在強風作用下方能量測到較明顯之高層建築結構變位。在近年並無強颱侵襲的情況下，本文暫以標的建築之風洞縮尺模擬試驗量測該建築物所受風力歷時，配合結構有限元素模式計算建築物頂樓反應歷時，並以此位移反應歷時作為振動平台之輸入，模擬實際高層建築之受風反應。研究結果顯示，以GPS與加速度計配合本文建構之數據處理方法，量測所得高層建築的受風反應行為，準確性明顯優於傳統上僅使用加速度計或單一採用GPS的量測結果。 The wind induced building vibration has both mean and dynamic parts. Therefore, besides employing accelerometer, an additional low-frequency sensitive instrument is necessary to acquire complete measurement of building behaviors under strong wind. A monitoring system consists of high resolution Global Positioning System (GPS) and accelerometers were built. A data processing scheme to merge the two signals was developed and calibrated. Then, a set of artificial building oscillation time history based on wind tunnel model test was applied on an uni-axial motion simulator to test this monitoring system. The results indicate that proper combination of GPS and accelerometer can achieve satisfactory measurement results of building’s behaviors under strong wind.
