捷運淡水線交通噪音預測模式之研究

Abstract

捷運系統開發前需依法提出環境影響評估報告書，其對營運後產生之交通音量，係利用預測模式來推估，若營運後之音量超過預測值太大，相關之預防措施〈如隔音墻〉將失去原訂之效能。近年來藉由電腦的快速發展和普及，相關噪音模擬軟體已在環境影響評估案中使用，惟至民國92年Peterson預測模式仍有人使用它，其是否有過人之優點，何以歷久不衰？另其使用上的限制為何？在相關大眾捷運系統境影響評估報告書中並未被論及。 本研究發現，將列車通過最大音量、車速、車長、通過班次及距噪音受體距離等資料輸入Peterson預測模式，即可推估均能音量，故具使用簡便性之第一項優點，另使用上並無特別的限制條件為其第二項優點。 由Peterson預測模式在捷運淡水線之預測值和實測值的差距，進而瞭解該預測模式在捷運淡水線之適用性。藉實際量測營運中捷運系統之交通噪音，再將測值使用SAS軟體進行迴歸分析，得到適用捷運淡水線淡水地區修正之Peterson預測模式為： Leq=(0.97207)*Lmax+(0.96862)*10log(R(1.5D+d)/V)-29.96167 若將上式各項係數之小數點以四捨五入進位為整數，則與原Peterson預測模式相符，顯示該預測模式適用捷運淡水線淡水地區。

The development of rapid transit system has to provide the environmental impact assessment report by law during the stage of permission application for the development involved. Within this the train passby noise of the rapid transit system post-completion use is predicted by estimation model. If the difference of the estimated sound level from that of the measurement is large, the desired performance on the prevention facility to be used〈such as sound barrier〉will be greatly reduced. The related software to the noise simulation is widely used to the environmental impact assessment because of the rapid growth of computer and its popularization in recent years. The Peterson’s prediction formula had been used to the assessment on environmental impact until 2003. Is there any excellent advantage in it? How does this model undergoes a long term usage and still not fade? What are the restrictions on its usage? It had not been stated in the environmental impact assessment report involved for the public rapid transit system. This study found that when we input the maximum level of train passby noise, the train speed, the train length, the number of trains and the distance of the receiver from the track centerline in the Peterson’s prediction formula, we can easily obtain the equivalent prediction sound level. The advantages of the Peterson’s prediction formula are that it can be simply used without any special restriction. We can certain the applicability of the Peterson’s prediction formula to Danshui line of the rapid transit system by verifying the difference of the estimation from the measurement. We also can use the SAS software to make the regression analysis. The data is measured from the train noise of the rapid transit system post-completion use. After getting the modified Peterson’s prediction formula, we can apply it to the Danshui line of the rapid transit system around the Danshui area: Leq=(0.97207)*Lmax+(0.96862)*10log(R(1.5D+d)/V)-29.96167 If we round the decimal point of various coefficients in the above equation to integral, the equation as modified is very coincident with the Peterson’s prediction formula. It is shown that the Peterson’s prediction formula is applicable to the Danshui line of the rapid transit system around the Danshui region.