도로 방음시설 계획절차와 대안결정에 관한 사례 연구

Abstract

Case Study on the Planning Procedure of Traffic Soundproof Facilities and Alternative Decision Making

Son, Jeong Jul

Interdisciplinary Program of Construction Engineering and Management Graduate School Pukyong National University

Abstract

The purpose of this study is to research on noise mitigation plans of tunnels as case study to improve residential living conditions near highway. This will provide fundamental data for engineering of noise mitigation tunnel in the future. The conclusion follows:

1. The traffic noise abatement procedure is shown as: Field study - Survey on current noise level - Establishing variety of plans for noise reduction - Selection on options to reduce traffic noise - Anticipate noise levels - Comparison with environmental regulations and requirements - Configuration of targeted noise level - Decision on appropriate noise reduction method - Evaluation on design - Implementation

2. Vertical noise barriers in multi-lane highway are proven to be impossible to attenuate noise to the targeted noise level of 20dB. Also, elevated vertical noise barrier can easily invade the resident's right of viewing and often result to civil-complaints. In the case of the noise reduction tunnel, it effectively blocks the path of noise, resulting effective containment of the noise. Therefore, it is appropriate to choose noise reduction tunnel over vertical noise barrier.

3. The research shows that the recent noise mitigation tunnels in Korea takes shape of an arch and were designed to fit the surrounding environment by using transparent panels and absorptive panels.

4. The design evaluation procedure is to be followed as: General estimation for noise reduction facilities - Exterior design - Appearance appraisal - Detail planning - Implementation The designs of the noise reduction facility should consider every aspect of its surrounding environment to fit in.

5. The noise reduction facilities are more effective in the lower levels of the residential buildings due to greater diffraction loss comparing to the higher levels of the residential buildings.

6. Low-noise pavement, installation of noise diffraction-edge modifier, installation of the vertical noise barriers and hybrid noise mitigation tunnels each shows 3%, 3.4%, 23.3% and 19.3% of noise level declines during day and 3.2%, 3.6%, 24.7% and 20.4% by night.

7. The correlation between noise level and the altitude of residential buildings were analyzed. Compare to pre-noise abatement, the noise level increases until 10th floor and shows tendency to decrease from then on with low-noise pavement and noise diffraction-edge modifier. Installing the vertical noise barrier gives over all of 23% of noise reduction effect but this effect gradually diminish in higher altitude of the building. The installation of hybrid noise mitigation tunnel confirms 20% of noise reduction and the noise level declines till 20th floor, but tends to converge above 20th floor.

In conclusion, it is suitable to construct noise mitigation tunnel rather than vertical noise barrier in the case of residential buildings above 20th floor as it is easier to construct, economical and structurally stable than vertical noise barrier. Furthermore it does not invade resident's right for viewing nearby highways, preventing the cause for civil complaints in advance.