• The Journal of the Acoustical Society of Korea
• /
• v.34 no.1
• /
• pp.52-59
• /
• 2015

In the conventional model for the prediction of the railway environmental noise, one used an empirical formula of the total noise level at specific distances. Only a function of the distance to the source was also used to calculate the noise level near the railway bridges. However, the noise varies depending on the position of the receiver as well as the distance from the source especially at concrete bridges. In this paper, a noise propagation model in the railway concrete bridge was derived by considering the diffraction at the bridge deck and the ground effect and applying the ISO 9613-2 noise propagation model. We compared the predicted and measured values of environmental noise at a high-speed railway bridge, and it was confirmed that this prediction model gives relatively small errors.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.91-98
• /
• 2007

Community noise has been serious social issues in Korea. This paper reviews current statistics and status on railway noise, with practical engineering tools in order to reduce the noise level from railway traffic noise sources. At the beginning, guidelines of the current environmental policy are discussed, with the new policy on railway noise to be enforced beginning in 2007 with 5 year schedule. Then, a noise reducer is proposed as a tool to reduce noise levels protecting people living near at the railway. Details on the acoustic effect in field test are discussed with the result of implementation in the street. We propose noise reducers as an effective and practical tool for the people who are exposed to rail traffic noise in cities.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.2 s.107
• /
• pp.156-162
• /
• 2006

For the reduction and efficient management of railway noise, first of all prediction of railway noise is necessarily requisited. Many studies for prediction of railway nearby noise have been accomplished. But it is impossible to predict easily and exactly for the Korean Railway, because the acoustic powers for each rolling stock operated in Korea have not been built yet. So in this study, Prediction model equation for environmental noise for Korean rolling stock Saemaeul was suggested using SEL of engine and rolling noise component separately. Finally for the validation of prediction equation, the predicted result was compared to the measured.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.371-376
• /
• 2005

For the reduction and efficient management of railway noise, first of all prediction of railway noise is necessarily requisited. Many studies for prediction of railway nearby noise have been accomplished. But it is impossible to predict easily and exactly for the Korean Railway, because the acoustic powers for each rolling stock operated in Korea have not been built yet. So in this study, prediction model equation for environmental noise for Korean rolling stock Saemaeul was suggested using SEL of engine and roiling noise component separately. Finally for the validation of prediction equation, the predicted result was compared to the measured.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.6-12
• /
• 2010

The source of wayside noise for the train are the aerodynamic noise, wheel/rail noise, and power unit noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The Structure borne noise is mainly a low frequency problem. The train noise and vibration nearby the elevated railway make one specific issue. The microphone array method is used to search sound radiation characteristics of elevated structure to predict the noise propagation from an elevated railway. In this paper, the train noise and structure borne noise by train are measured. From the results, we investigated the effect on the sound absorption tunnel for elevated railway.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.843-848
• /
• 2011

Planning and construction of railway for high speed trains up to 400 km/h are recently driven in Korea. High speed train is one of the environment-friendly fastest mass transportation means but its noise generated by rolling, traction and aerodynamic mechanism can cause public complaints of residents nearby railways. To cost-effectively prevent the troublesome noise in a railway planning stage, the rational railway noise prediction method considering the characteristics of trains as well as railway structures should be required but it is difficult to find authentic methods for Korean high speed trains such as KTX and KTX-II. In this study, we propose a framework of our own railway noise prediction model emitted by Korean high speed trains over 250 km/h based on the recent research results carried out in EU countries. The model considers railway sound power level using several point sources distributed in heights as well as tracks, whose detail speed- and frequency-dependent emission characteristics of Korean high speed trains should be determined in near future by measurement or numerical analysis. The attenuation during propagation outdoors is calculated by the well-known ISO 9613-2 and auxiliary methods to consider undulated terrain and wind effect.

• International Journal of Railway
• /
• v.4 no.2
• /
• pp.42-49
• /
• 2011

Today, rolling stock has become a fast and convenient mode of transportation and has witnessed increased demand. But the speed improvement has resulted in increased aerodynamic noise and therefore residential districts near the railroad tracks are exposed to ever increasing noise level. A study on methodologies for measuring and appraising rolling stock's environmental noise has therefore become an important area of endeavor. In the case of the environmental noise, there are no changes in tone so prediction can be made by reducing areas around the railway. The present study explores estimation of the noise around the railway using scale model, and the source of the noise has been investigated as well. The scale model of rolling stock will have to be able to measure high frequency noise and it is required to be generated in a short amount of time. Since popping a balloon or firing a gun fits this requirement the present study analyzed the characteristics of these two different noise sources. Measurement was made in a large vacant lot and the reflection due to the ground was also examined. The method proposed here can be used in the future for predicting the environmental noise of railway vehicles.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.667-672
• /
• 2007

The source of wayside noise for the train are the aerodynamic noise, wheel/rail noise, and power unit noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The Structure borne noise is mainly a low frequency problem. The train noise and vibration nearby the elevated railway make one specific issue. In this paper, the train noise and structure borne noise by train are measured. From the results, we investigated the effect on the sound absorption tunnel for elevated railway.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.50-55
• /
• 2006

For prediction of railway noise, propagation characteristics must be identified as well as the source characteristics. During the railway noise in outdoor pass the air, various factors affect the propagation. In this study, to suggest more effective and convenient equation to predict railway noise, calculation method for correction factor was investigated.

• Journal of Environmental Impact Assessment
• /
• v.20 no.6
• /
• pp.787-795
• /
• 2011

Noise barrier is generally used with welding of joint rail for railway noise reduction in our country. But the noise barrier for high speed railway has weak point in low frequencies about 315Hz band. In this study, For developing of Interference-type Noise Reduction Device(INRD), acoustic analysis were performed using commercial software. For verifying the improvement in the noise reduction, noise measurement before and after installing of INRD were performed in Anechoic Chamber. From these acoustic analysis and noise measurement, it was known that developed INRD has a good noise reduction performance and can be used efficiently with conventional noise barrier.