PURPOSES : The computational fluid dynamics of flow and fine particles in a road were set to determine the insert flow and occurrence characteristics.METHODS: The road extension was 100 m with two lanes. A one-ton truck traveled a 50-m distance. After a noise barrier was installed on one side of the road, the flow and a collision analysis were tested.RESULTS: The flow that occurred was 5 m/s beside the vehicle, and fine particulate was 5.0×102 μg/m3 after 20 m from the exhaust vent.CONCLUSIONS: After a collision analysis of the fine particulate on the noise barrier to find the most suitable position of the filter panel in height, the bottom 1 m was the most optimum position because 88.1% of the distribution was concentrated there.

Recently, the damage caused by typhoons and strong winds, which frequently occur as a result of global climate change, is on the rise. Soundproofing and windshield walls installed on roads often fail to function because of damage due to strong winds. Therefore, in this study, strong wind fragility evaluation was performed to predict the probability of failure of soundproof / windproof walls from wind loads. A three-node bending experiment was carried out to investigate the material characteristics of the aluminum frame which was installed on the actual soundproof wall. Based on the results of this experiment, the resistance performance of target structure was calculated, and the frame damage was selected as the performance limit state. Wind loads acting on 4m x 1m individual element soundproof wall was compared with the resistance capacity by Monte Carlo simulation method. In the future, the evaluation of the strong wind safety of the sound barrier structure should be proceeded by setting the limit state and performing the vulnerability evaluation through the additional experimental data. This work can become guideline information for future design of soundproof and windproof wall.

It is known that air pollutants such as fine dust and exhaust gas from vehicles are harmful to human health. In particular, the black carbon emitted by vehicles is known to cause a large number of premature deaths. This study analyzed the effect of a noise barrier on the inflow amount of black carbon from a nearby high traffic road to a school area, using numerical analysis performed at two elementary schools. Also, the correlation between the noise barrier’s shape, height and the inflow amount of black carbon was assessed. As a result, it was found that the higher the noise barrier, the lower the inflow amount of black carbon observed at the school A. However, the inflow amount of black carbon at school B was not greatly influenced by the height of the noise barrier. The inflow amount of black carbon at the schools could be changed not only by the height of the noise barrier, but also by the shape, height and position of the noise barrier and the school building.

PURPOSES : The noise, which is typically generated by fast moving vehicles, can be intercepted by installing a noise barrier with a soundproof panel. However, reflections from the panels cause secondary noise, and hence lower the effectiveness of the panels. In this study, the reduction of reflection noise by considering the shape, especially zigzag one, of the soundproof panel have been evaluated. METHODS : The simulation model used in this study was Nord2000, which simulates real-road situations effectively. Based on the simulation results, the joining angle of 133。with the pattern width (a) equal to 2 m and the projection height (b) equal to 0.5 m was adapted in the zigzag shape as the best profit designing factors. RESULTS: The measuring results at middle height, 15 m showed reduction at all points except the point with average -1.6 dB. At a greater height of 30 m, 2 points showed reduction. A real-sized facility was constructed to investigate the reflected sound from a zigzag shaped panel up to the height of 5 m. CONCLUSIONS: The reduction effects were detected in all the receive points in the range of 2-6 m distances and 1-5 m heights comparing the plane panel. Compared to plane panel, the noises are reduced at an average of 2.4 dBA.

PURPOSES : A study on the efforts to minimize the road traffic noise has been underway. An attempt has been made to measure the noise level using a noise map; however, the attempt is limited to certain areas only. In general, a noise barrier is employed to prevent road traffic noise; however, unplanned noise barriers developed without considering the surrounding environment, including excessively high walls, cause problems such as infringement on prospect right. Noise ceiling at daytime in Korea is 68 dB(A), which is relatively higher than in other countries. METHODS: The noise barrier used mainly for road noise reduction was analyzed to estimate the optimal height. Related variables such as road width, the height of the upper part, distance to the building, and angle (for instance, 30。). RESULTS : A formula to calculate the optical height of the noise barrier, considering the road environment (i.e., parameters such as road width and distance to building), was developed in this study in an attempt to mitigate the noise generated from the road. CONCLUSIONS : The formula to calculate the noise barrier is expected to lead to cost saving, accurate installation of barriers, and protection of the right of prospect.

Noise barriers along the road do not only block the traffic noise but also prevent traversing the car exhausts. These barriers may affect air pollution dispersion, leading to increase vertical mixing due to the upwind deflection of air flow caused by the noise barriers. In this study we investigated the air pollution dispersion around multi-noise barriers using commercial software FLUENT. Investigated cases were 8 cases which had from zero to three noise barriers and two emission sources. Simulated results show noise barriers increase the vertical air pollution impact distance larger 1.7~2.1 times than that of no barrier case. It was also found that noise barriers decrease the horizontal air pollution impact distance lower 0.6~0.8 times than that of no barrier case.

지난 2016년 12월 발표된 제1차 기후변화대응 기본계획(2017∼2036)에 따르면 우리나라는 효율적 기후변화 대응을 통한 저탄소 사회 구현을 목표로, 저탄소 에너지의 보편화, 기후산업의 주류화 등의 다양한 정책을 수립하여 국가 기후변화대응을 위한 지속적인 노력을 기울이고 있다. 이러한 노력으로 태양광 발전 관련 산업이 발전하고 있으며, 구조공학 분야에서도 태 양광 방음벽 등의 설치가 증가하고 있는 추세이다. 그러나 최근 국지적인 돌풍에 의한 산업시설물의 외장재 및 방음벽 피해 가 빈번히 발생하고 있는 추세이다. 본 연구에서는 과거 40년 이상의 기상관측자료를 이용하여 기후변화에 따른 풍속의 특 성을 조사하였고, 풍동실험을 통해 방음벽의 모서리 형상 변화에 따른 풍하중의 특성을 조사하였다.

This study was carried out on the upgrading of the noise barrier top device developed by 400km/h high speed railway infra research. By modifying the inner shape of the top device installed on noise barrier top, the performance of the first-stage top device was improved, and the weight was greatly reduced as compared with the first stage top device. In addition, the upper part was completed without an installation fixture by the integral method, and the construction was greatly improved. Finally, the upgraded top device was installed on the HONAM high speed railway site and its performance was verified.

소음 저감을 목적으로 설치되는 방음벽은 크게 흡음판과 방음판으로 나뉘며, 일조 및 경관을 저해하는 방음벽의 문제점을 해결하 고자 투명 방음벽을 설치하는 것이 일반적 추세이다. 방음벽에 사용되는 투명 방음판의 소재는 여러 가지가 있으나 경우에 따라서는 황변현상 과 재질변형 등으로 인해 투명도가 떨어지고 오염이 심해져 오히려 도시미관을 해하기도 한다. 따라서 이러한 단점을 보안하기 위하여 투명 방 음판의 재질을 접합강화유리로의 대체가 가능하다. 본 논문은 메트로 지하철 고가교 상에서의 열차 유발진동에 따른 접합강화유리 방음판의 진동 및 풍하중에 의한 안전성을 분석하고, 접합강화유리 시스템 및 재료에 대한 휨능력 성능시험, 압축강도 및 탄성계수 시험, 충격시험 등을 수행하여 접합강화유리의 방음판으로서의 적정성을 평가하는 데 목적이 있다.

In this study, will evaluate the performance of noise reduction devices for next generation high speed railway system of a train which has maximum speed over 400km/h. The core soundproof devices are the absorption block which reduces the reflection noise from concrete slab track and the interference device installed the top of noise barrier. Two types devices will be verified at 400km/h test section according to studied performance assessment at Hwang-san Kim-jae Chonbuk, Jeonbuk, Korea.