捷運系統已是許多城市積極發展的大眾運輸系統，它非常便利及快速，但伴隨而來的是列車行駛時產生的噪音。本文探討軌道高架橋振動及結構噪音的特性，以台北捷運U型混凝土高架橋在列車通過時所造成的結構振動產生噪音。
首先分析高架橋結構橋面板及側牆的振動頻率響應，討論列車通過容易激發之自然振動模態，並觀察其模態振型。討論聲壓頻率響應與振動頻率響應的差異性，觀察這些自然頻率的模態振型與聲場分佈的關係。此外，討論結構噪音在高架橋上方、下方、水平方向聲壓位準隨距離衰減的情形，討論高架橋下有與無地面對於聲場有何影響。最後在鋼軌下加入高隔振基鈑，討論振動及結構噪音降低的情形。本研究結果顯示地面反射聲波的影響，聲壓位準在地面上方4公尺以上受地面反射影響不大；以距左側軌道中心水平距離15公尺觀察噪音，使用高隔振基鈑可降低聲壓位準3.3dB(A)。

The metro system has long been a public transportation system for city development. This convenient and fast transportation system creates the noise problem while the trains are moving. This paper investigates and explores the features of viaduct vibrations and structure-borne noise using a Taipei Metro System U-shaped viaduct model.
Firstly, the frequency response of deck and the side walls of viaduct was analyzed. the modes natural vibration may be predicted by the trains pass by. Secondly, the differences between sound pressure frequency response and vibration frequency response were compared and analyzed and the relationship between the modal shape and sound field distributions were observed. In addition, the decrease of structure-borne noise with the increase of distance was examined in upward, downward, sideward directions. The effects of ground reflection on the noise level was also discussed. Finally the effects of NBHI on the noise attenuation was also investigated. Results of this study showed that, the effects of ground reflection on the noise level in 4 meters above the ground can be neglected for acoustics field. To observe the noise of 15 meters horizontal distance from the center of the track, NBHI can reduce the sound pressure level about 3.3dB.

目錄
摘要 i
Abstract ii
表目錄 v
圖目錄 vii
第一章緒論 1
1.1 研究目的 1
1.2 文獻回顧 2
第二章振動與噪音理論介紹 4
2.1 振動特性簡介 4
2.3.1快速傅立葉轉換(Fast Fourier Transform, FFT) 8
2.2聲學理論 11
2.2.1聲強 11
2.2.2音量的表示 12
2.2.3三分之一倍頻頻譜 13
2.2.4聲音的加權 17
2.3軌道系統的噪音計量 19
2.4 SYSNOISE邊界元素法分析系統 21
第三章有限元素模型驗證與比較 23
3.1平板有限元素模型 23
3.2平板模態分析與比較 25
3.3聲場分析與比較 26
3.4網格影響檢討 29
第四章行駛列車引致高架橋結構噪音分析 35
4.1高架橋模型 35
4.2軌道模型 37
4.3列車模型 38
4.4模態分析 40
4.5 SYSNOISE聲場分析 49
4.5.1 分析參數設定邊界元網格建立 49
4.5.2列車對軌道入力 53
4.6數值分析流程 56
4.7高架橋結構振動聲場分析結果 57
4.7.1不同位置之振動頻率響應比較 61
4.7.2聲壓頻率響應比較 76
4.7.3結構噪音的衰減 88
4.7.4加入地面反射面的差異比較 97
4.7.5高隔振基鈑對於振動及噪音的改善 106
第五章結論與展望 109

A.R.Crockett and J.R Pyke, 2000, Viaduct design for minimization of direct and structure-radiated train noise, Journal of Sound and Vibration,231(3): 883-897.

F. Augusztinovicz, F. Marki, K. Gulyas, A.B. Nagy, P. Fiala and P. Gajdatsy, 2006,Derivation of train track isolation requirement for a steel road bridge based on vibro-acoustic analyses,Journal of Sound and Vibration, 293:953-964.

F. Augusztinovicz1, F. Marki, P. Carels, M. Biteand I. Dombi, 2003, Noise and vibration control of the South railway bridge of Budapest, Tenth International Congress on Sound and Vibration, 1713-1720.

K. W. NGAI and C. F. NG, 2002, Structure-borne noise and vibration of concrete box structure and rail viaduct, Journal of Sound and Vibration, 255(2):281- 297.

L.G Kurzweil, 1977, Prediction and Control of Noise From Railway Bridges and Tracked Transit Elevated Structures, Journal of Sound and Vibration, 51(3):419-439.

Patrick Vanhonacker, 1998, Structure Borne Noise Reduction of a Metro Steel Bridge, In The16th International Modal Analysis Conference. SEM. 1556-1559.

Q.Li, Y.L. Xu and D.J. Wu, 2012, Concrete bridge-bornelow-frequency noise simulation based on train-track-bridgedynamicinteraction. Journal of Sound and Vibration 331:2457-2470.

Qi Li, Jiang-long Han and Ding-jun Wu, 2011, Survey on predicting and controlling of structureborne noise from rail transit bridges, Electric Technology and Civil Engineering (ICETCE), 4559- 4563.

行政院環境保護署法規委員會, 2008, 噪音管制法,公告日期:2008.12.3.

行政院環境保護署法規委員會, 2009, 噪音管制區劃定作業準則, 公告日期:2009.09.04.

張羽茹, 2000, 高速鐵路高架結構系統振動噪音調查與分析, 碩士論文, 國立台灣海洋大學系統工程暨造船學研究所。
陳子軒, 2011, 動力機械之聲功率量測, 碩士論文, 國立台灣大學工程科學暨海洋工程學系.

陳昭延, 2010, 捷運環狀線電聯車概念設計架構簡介, 捷運技術半年刊, 第43期: 9-22

曾士豪, 2009, 高音小號音準模擬分析與實驗, 碩士論文, 國立中央大學機械工程學系.

黃勢淵, 2009, 台鐵系統振動噪音調查與分析, 碩士論文, 國立台灣海洋大學系統工程暨造船學系.

葉育超, 2004, 內支承及附加集中質量對平板聲輻射改善之研究, 國立台灣大學工程科學暨海洋工程學系。