摘要 當高速列車通過高架橋時，對橋墩產生衝擊能量，此衝擊能量會傳遞至基樁，並迅速地由樁身傳遞至樁尖，於承載層形成振源，向周圍擴散傳播。因此，本研究目的為直接透過對橋墩下的基樁做改良（減振基樁），使得基樁本身就能夠達到減振的效果。 根據前人的研究顯示單一彈簧減振器之效果最明顯，但其最大動態變位量卻甚大。因此，本研究採用液壓減振器，將其安裝在基樁上改良成減振基樁，並進行一系列的模型試驗。 實驗的結果得知，純彈簧之阻尼器能夠達到的減振效果最為明顯，但其最大的動態變位量已經高達5.14mm。而改為填充液體後，可將最大動態變位量抑制在0.5mm以下，並還能達到減振效果，尤其是填充機油(油料高度為3.0cm)的減振器，減振成效由1.75g下降至0.50g，而且最大動態變位量只有0.224mm。因此，液壓減振器能夠達到減振成效，同時可抑制最大動態變位量。 關鍵詞：減振基樁、液壓減振器、振波、動態變位量。 Abstract Impact or shock will be applied to piers of viaduct while bullet trains pass through. The impact energy will be transmitted to the pile shaft and then transferred to the pile tip. A new vibration source will be formed in bearing layer, and spread the vibration waves to the surrounding area. The purpose of this study is to improve the pile foundation to reduce this kind of vibration. According to the previous studies, it is understood that a single spring shock absorber has an obvious improving effect, but the amount of dynamic displacement may exceed the determined value of designing code. Thus, this study used a hydraulic shock-absorber, installed on the head of pile to reduce the shock or vibration energy. The results of experiments shows that the pure spring vibration damper can achieve the best result of vibration suppression, but the maximum amount of dynamic displacement is 5.14mm, the value limited by the designing code. However, if the shock-absorber is filled with oil, the maximum dynamic displacement can be decreased to the value of 0.5mm. Especially for the shock-absorber filled with the machine oil (oil height=3.0cm), the peak acceleration at pile tip can be decreased from 1.75g to 0.50g, and the maximum dynamic displacement is only 0.224mm. Therefore, the hydraulic shock-absorber can achieve the purpose of reduceing vibration and keep the dynamic displacement within a small value. Keywords: pile of vibration suppression, hydraulic shock-absorber, shock wave, dynamic displacement
