簡諧點荷重之基盤反應

Abstract

本研究主要之目的為探討環境外力對於台灣光子源屏蔽隧道區所產生之波傳振動問題。 本論文為採用有限元素法套裝軟體ABAQUS，以三維模型進行頻率域分析。首先須驗證ABAQUS軟體分析波傳問題之精確性，接著再以收斂性分析之結果建立實際案例模型，針對簡諧點荷重作用下的強迫振動進行數值模擬。 最後，在實際案例分析中，將分為三個主題來探討，第一個主題為對於無開挖之土壤，有無放置屏蔽隧道區之比較，結果顯示有放置屏蔽隧道區之位移反應會較小；第二個主題為對於全開挖之土壤，有無放置屏蔽隧道區之比較，結果顯示有放置屏蔽隧道區之位移反應會較小；第三個主題為對於放置屏蔽隧道區之後，土壤有無開挖之比較，結果顯示全開挖之土壤其位移反應會較小。 而在實際案例2分析中，對於半開挖之土壤，有無放置加速器環館之比較，結果顯示在鉛垂向振動所產生之位移，其測點A之R方向位移會變小，Z方向位移為變大，而測點B之位移則皆為變小；在水平向振動所產生之位移，不論是在測點A還是測點B，其R方向位移皆會變小，Z方向位移則會有兩種情況，在低頻時變小，高頻時變大。

The main goal of this research lies on analyzing wave propagation problem at the storage ring tunnel of Taiwan Photon Source. The finite element program ABAQUS is selected for analysis. First, we set up an ideal model and analyzed it to obtain numerical solutions by changing element sizes and domain sizes. Then we compared the numerical solutions with the theoretical solutions in order to examine the accuracy and convergence of the program. After that, we discussed how to select proper parameters to model the real situations. And then, wave propagation in half-space medium caused by harmonic point load is analyzed. In these analysis, the results for the case without tunnel will be compared with that with tunnel, and the results without excavation will be compared with that with excavation. By the comparisons, one can observe that the vibrations, for the case with tunnel and the vibrations for the case with excavation are smaller.