列車引發高架橋噪音分析

Abstract

台北市隨著都市化的發展，人口不斷向大都市湧入，造成交通擁塞及車輛廢氣排放，為了改善交通狀況，縮短上下班時間，將乘客有效分流至各個目的地，捷運的興建成為重要的公共設施。高度人口密集的都市，捷運路線接近民宅，噪音已經成為市民心中嚴重的環境公害之一，振動噪音問題逐漸為市民所重視。有效降低振動噪音、提升環境品質，為市民謀取福利，成為現下重要的課題。 本文以平板振動與噪音實驗結果驗證本文板結構振動FEM分析與聲場BEM分析之模型可信度，進而比較列車位於不同橋梁位置對整體結構模態之影響，確認在列車經過高架橋之合理分析狀態，以暫態分析模擬列車通過高架橋軌道系統對軌道衝擊所造成之軌道入力進行高架橋結構振動引起的環境聲場分析。比較不同基鈑所造成之軌道結構振動及其造成噪音之聲壓位準差異，檢討高隔振彈性基鈑之減振狀況及降噪功能。

The urbanization in Taipei City. It causes a serious traffic problem, including emission of vehicle exhaust and noise. To improve the traffic conditions, building MRT becomes imperative infrastructure. The flow of passengers could be effectively channeled into distinctive destinations and the time spent on the communication is reduced as well. Even though MRT contains various fascinating merits such as high transit, little pollution, fast speed, energy- saving and low carbon emission, it still brings about some environmental problem like noise pollution. Therefore, it is a critical issue to effectively reduce noise pollution from vibration and to provide comfortable transportation system. In the thesis, the finite element model for plate vibration analysis and the boundary element model for analysis of acoustic field excited by vibration plate haven verified by an experiment result and analytical solution of a plate panel. The transient dynamic analysis to simulate the vibration of a viaduct rail system impacted by passing train has been performed, and the impact force on the track system were adopted from the analysis results. The spectrum of the impact force is used to input force for acoustic field analysis around viaduct. The effects of NBHI on the mitigation of track impact force and noise radiated from vibrating viaduct has investigated.