This study performs material nonlinear analysis of connection parts at noise barriers, which have a light weight. Subsequent numerical simulation results for three types of models (standard, double, and standard models strengthen by ribs) present that the applied connections for target noise barriers constructed show suitable structural performance. In this paper, the existing finite element elastic stress analysis using the ABAQUS program is further extended to study the plastic stress distribution of the noise barriers. The numerical results for various parameters are verified by comparing different steel types with stresses occurred in the noise barrier from the numerical simulation.

Recently, the damage caused by typhoons and strong winds are increasing due to the world climate change. Considering the vulnerability of structure to strong wind disaster, in this study, we focused on the soundproof wall among vulnerable wind facilities. GFRP was chose as the reinforcement frame among the components of the soundproof wall. The modeling of the soundproof wall was made using the finite element commercial analysis program ABAQUS and the resistance performance was estimated through the optimal model analysis of the soundproof wall. Wind loads were calculated using Monte Carlo Simulation. Finally, wind fragility evaluation was performed to predict the degree of damage of the GFRP frame soundproof wall. It is necessary to verify the performance of the GFRP frame through comparison with the aluminum frame which is generally used in the construction of the soundproofing wall.

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.

Climate change resulted in the growing occurrence frequency of typhoons, and the damage it caused was also increasing. In this study, the soundproofing and windproof walls installed on the domestic road were modeled by using ABAQUS, a commercial finite element analysis program. Correspondingly, steel column, aluminum frame and transparent acrylic plate were modeled. Based on the result from individual part of soundproof wall model, the number of soundproof wall parts for optimal design was determined to be five parts. The design standard of road construction barrier was applied to this optimum model to perform the safety evaluation for strong wind disaster. In the future, it will be possible to improve the guidelines for design of soundproofing walls in Korea by carrying out further experiment to increase the reliability of safety evaluation of soundproofing walls.

Recently, the damage caused by typhoons and strong winds frequently displayed according to world climate change tends to be increasing. In the case of soundproof / windproof wall installed on the road, frequent occurrence does function for damage due to strong wind. As a result, in this study, strong wind fragility evaluation was performed to predict the degree of damage of strong winds of soundproof / windproof walls. We were conducting research focusing on the destruction mode in which the overall destruction of the sound barrier caused by the destruction of the aluminum frame occurs. Three node bending experiments were conducting for grasping the material properties of a soundproof wall aluminum frame that is currently being constructed on a road. Based on the results of this experiment, the resistance performance of the target structure was calculated, the frame breakage was selected as the limit state, and the wind load acting on the simplified soundproof wall model was measured using the Monte Carlo model model technique to measure.From now on, through the additional study, it will be necessary to proceed with a more accurate evaluation of the safety against strong windsof the soundproof wall structure using the vulnerability evaluation execution and the setting of the limit state.This study is expected to be the basic data of the study on prediction technique of wind - induced damage of soundproofing and windshield walls in the future.

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 purpose of this study is to evaluate the effect of the quiet pavement on reducing a barrier height by using a prediction tool called SoundPLAN. METHODS: Firstly, the prediction was carried out to evaluate the difference in the maximum noise level at a building facade between the normal and the quiet pavements without a barrier. After calculating the noise reduction effect by the quiet pavement, a comparable barrier height to obtain the same noise reduction effect with it was predicted according to designable factors including road-building distance(10 m, 20 m, 40 m) and road-barrier distance(5 m, 10 m, 20 m, 30 m). RESULTS: The result showed that within the considered designable factors, the maximum barrier height was 37 m, 52 m, and 55 m to have the same noise reduction effect by the quiet pavement reducing 1 dBA, 3 dBA , and 5 dBA, respectively. It was evaluated that the barrier height increased with the increase of the road-building and road-barrier distances. To simulate the real situation in urban areas and to evaluate the combined effect of the normal/quiet pavement and barrier, the barrier height was fixed as 6 m. It was predicted that the noise level would reduce to as low as 0.2 dBA by the combination of normal pavement and barrier. On the other hand, the combination of the quiet pavement and barrier reduced 1.2 dBA, 3.2 dBA, and 5.2 dBA, respectively, for quiet pavement reducing 1 dBA, 3 dBA, and 5 dBA. CONCLUSIONS: A guideline needs to be suggested to select appropriate noise abatement schemes by considering factors such as the roadbuilding and road-barrier distances.

소음공해를 방지하기 위한 방음시설물로서 도로, 철로 및 공항 주변에 설치되는 방음벽은 주로 외부에 설치되어 풍하중에 노출된다. 지속적이고 반복적인 풍하중은 방음벽의 피로를 야기하며 높은 풍속이 발생할 경우 붕괴되는 경우도 흔히 발생하고 있다. 본 논문에서는 반사형, 통풍형 등 방음벽의 유형별로 방음벽에 작용하는 풍하중의 발생 과정과 내풍성능 개선방안에 대해서 전산해석을 수행하였다. 통풍형 방음벽의 경우 수압면적이 감소한 것에 비하여 풍하중은 다소 낮은 6.76%의 감소율이 나타난 원인은 풍하면의 통풍공 주변에 발달한 국부적 부압으로 판단되었다. 추가적인 풍하중 저감을 위하여 박리에 의한 와류의 규모를 개선하기 위한 방안으로 상부에 슬릿을 설치한 결과, 최대 14.67%의 감소효과를 나타내었다. 또한 슬릿의 간격이 250mm일 때 15.41%로 풍하중이 감소율이 상대적으로 우수하였으며, 이는 방음벽 상단과 슬릿에 의한 기류의 상호작용이 와류의 규모와 발달에 영향을 미친 것으로 판단된다.

도로에 인접한 아파트 주동을 대상으로 일반 도로포장 대비 저소음 도로포장의 소음저감효과를 예측한 후, 일반 도로포장 시 이에 상응하는 소음레벨 저감을 위한 방음벽 높이를 예측하여 저소음 도로포장의 경제성 분석을 위한 기초연구를 수행하였다. 5dBA의 소음저감효과를 나타내는 저소음 도로포장 설치조 건에 대한 예측결과 최대 54m의 방음벽 높이를 저감시킬 수 있는 것으로 예측되어 도시미관 및 경제성 측면에서 효과적인 것으로 분석되었다.

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.

PURPOSES : This study is to suggest future development direction and application of environmental noise barriers as multi-functional soundproof wall. METHODS : Based on the literature review, case study and patent search, research and patent trend were investigated. Patent search was conducted by Patent searching tools, 'Focust'. RESULTS : As environmental noise barriers, Vegetative soundproof wall, photovoltaic soundproof wall, and air-pollution reduction soundproof wall were investigated. First of all, In Korea, Vegetative soundproof wall is being developed mostly as soundproof wall that has vegetation foundation inside, to meet the domestic condition with 23 patent applications. Second, Photovoltaic soundproof wall is being developed mainly with efficiency of photovoltaic system rather than soundproofing. And it is limited to one generation solar cell technology, although Solar cell technology is developing at a rapid pace. On the other hand, for reducing air-pollutant by soundproof wall, a variety of methods are being suggested (filtration, adsorption, and photocatalytic oxidation), and one of them, adsorption are applied for developing air pollution reduction soundproof wall in Korea. CONCLUSIONS: The above soundproof wall is not simple structure, but road facility applied fusion technique. Therefore, as one system, it is difficult to harmonize due to various considerations for design factor. However, if it's possible that a benefits of one system apply to another system, Synergy effect may be created. In the foreseeable future, soundproof wall may be considered as a road system using fusion technique rather than just functional facility. Therefore, substantial studies for applying multi-functional soundproof wall on the road are needed for the future.

최근 방음벽의 높이를 높이지 않고 차음 성능을 향상시키기 위해 방음벽 상단 소음저감장치의 설치가 늘어나고 있다. 이러한 소음저감장치의 음향적 성능평가 방법으로는 현재 고속도로에 적용되는 소음저감장치에 대하여 실시되고 있는 한국도로공사 도로교통연구원의 「고속도로 방음벽 소음저감장치의 감음성능 시험 및 평가방법」이 있다. 그러나 다양한 종류의 소음저감장치 제품이 계속 출시되고 있음에도 불구하고, 이를 구성하는 재질에 대한 성능기준은 아직 마련되지 않은 실정이다. 이 연구에서는 방음벽 상단 소음저감장치의 품질기준 도출을 위하여 비음향적 성능에 대한 시험방법 및 평가기준을 검토하였다. 소음저감장치의 내하중 시험과 관련하여 일본에서는 제품별로 심사 증명을 받거나, 자체적인 성능 시험 을 실시하는 것으로 알려져 있다. 소음저감장치의 다양한 형상과 크기를 감안하여 하중체를 사용한 등분포 하중시험방법을 검토하고, 시험방법의 적용성 평가를 위해 2m, 4m의 지주 간격을 갖는 시험용 지지대 2종을 제작하고, 동일한 소음저감장치 제품을 각 지지대에 설치한 후 재하 시험을 실시하였다. 시험 결과, 제품이 동일하더라도 설치되는 지주 간격이 넓어짐에 따라 소음저감장치 및 고정부에 대한 하중부하가 크게 증가함을 확인하였다. 소음저감장치에 대한 하중 재하 시, 캡 플레이트의 변형이 안전성에 미치는 영향이 크다는 점을 감안하여 캡 플레이트 부위(길이 방향 중간 지점)에 대하여 시험하중, 최대 변위량 기준을 방음판 기준을 참고하여 적용하고, 외형의 이상 여부(깨짐, 꺾임, 부품 탈락 등)를 확인하는 방법을 제안하였다. 금속재 방음판 한국산업규격에서는 부식 방지를 위해 전면판 재질을 알루미늄 및 알루미늄합금판(두께 1.6 ㎜ 이상), 용융아연도금강판(도장 제품에 한하며, 두께 0.6㎜ 이상의 SGCC)으로 한정하고 있으므로 소음저감장치도 이를 준용하고, 소음저감장치를 지주에 고정하는 데 사용되는 캡 플레이트에 대해서는 방 음판 후면판 재질(두께 1.6 ㎜ 이상의 SGHC)의 아연 도금 양면 최소 부착량 기준(Z27 이상)을 준용하여 적용하는 것으로 제안하였다. 금속재에 컬러 도장을 실시한 경우, 「방음판-금속재 컬러(KS F 4770- 2)」의 도막 품질 기준(염수분무시험, 촉진내후성시험, 밀착성시험)을 준용하되, 소음저감장치는 방음벽에 비해 빛의 반사로 인한 운전자의 시야 방해를 일으킬 가능성이 낮으므로, 광택도 항목은 제외해도 무방할 것으로 판단된다. 한편, 얇은 두께의 플라스틱 제품은 휨이나 뒤틀림으로 인해 외관 불량이 발생하기 쉬우므로, 「방음판 -비금속재 컬러(KS F 4770-3)」에서 규정하는 전면판의 최소 두께 수준(2㎜ 이상)과 후면판의 내후성 기준(형광UV시험 500시간 또는 자외선카본시험 600시간 후 황변도 3 이하)의 준용을 제안하였다.

국내의 방음시설은 비교적 저렴하고, 설치 및 시공이 간단한 방음벽에 초점이 맞춰져 왔다. 특히, 반사형 방음패널의 경우 흡음형 방음패널과 같은 불투명형 방음벽과는 달리 시야를 가리지 않으므로 방음시설을 요구하는 거주자들에게 인기를 얻고 있다. 그러나 흡음의 효과가 거의 없어 방음벽을 설치한 반대측의 거주자에게 2차 피해를 야기할 수 있다. 따라서 반사형 방음패널의 형태를 개량하여 시야를 가리지 않는 범위에서 피해를 줄일 수 있는 방안마련의 필요성이 제기되고 있다. 이에 반사형 방음 패널의 전면 형상 및 기하학적 형태를 변화시켜 반사음의 전달이 방음벽 설치 반대방향으로 나아가는 것을 최소화 시킬 수 있는 형상을 도출하고자 하였다. 설계형상 및 설계인자는 그림 1과 같으며, 반사소음 평가는 방음벽이 설치되지 않은 맞은편 도로의 15m(R1), 30m(R2)높이를 목표지점으로 설정하였다. 추가로 도로내측(R3)의 경우 평판형 대비 소음이 증가여부를 확인하기 위하여 선정하였다. 방음벽 설계인자는 표 1에 제시하였으며 위 경우의 소음도를 예측하였다. 그 결과 방음벽 A와 B의 경우 평판 형에 비해 R1지점에서 반사소음을 저감하는 것이 확인되었으며, 특히 A의 경우 2.2 dB(A)의 소음이 감소되어 가장 좋은 결과를 나타내었다. R2지점은 0.2~0.7dB(A)의 소음이 증가하였고, B와 C방음벽은 모든 지점에서 0.1~0.2 dB(A)의 소음이 증가하였다. 결론적으로, 방음벽의 설계인자에 따라 반사소음 증감이 나타났고 방음벽 설계인자중 θ값이 작을수록 저감효과가 좋은 것을 확인하였다. 따라서 방음벽 형상에 따른 반사소음저감 기술개발의 가능성을 확인하였다.

도시화가 가속화됨에 따라 도로주변의 주거지역 개발 및 교통량 증가로 도로소음피해가 점차 증가하고 있다. 이에 소음피해의 대책으로 방음벽 설치 수요가 증가하고 있는 추세이다. 방음벽은 특성 및 재질에 따라 다양한 형태로 분류되며 크게 흡음형과 반사형 방음벽으로 구분 할 수 있다. 이중 반사형 방음벽의 경우 주변경관과의 조화성이 높으며, 특히 투명형의 경우 조망권 확보가 유리하다는 장점이 있어 최근 투명형 방음벽의 설치요구가 증가하고 있다. 그러나 반사소음의 영향을 받을 우려가 있는 지역의 경우 설치에 제한이 있다는 단점이 있다. 본 연구에서는 반사소음 저감을 위하여 방음벽 형상에 따른 소음저감 효과를 수학적 모델을 이용하여 시뮬레이션 하였다. 소음저감 목표지점은 방음벽 맞은편 5m(R1), 15m(R2) 높이와 도로내부(R3)등 3개 지점으로 선정하여 일반 평판형 방음벽대비 형상방음벽의 반사소음저감을 평가하였다. 시뮬레이션 결과 R1지점에서는 평판형 대비 형상방음벽에서 2.2 dB(A)의 소음이 저감되었으며 R2지점은 0.7 dB(A)의 소음이 증가하였고 R3지점은 소음의 증감이 없었다. 주파수별로는 R1과 R2의 경우 63 Hz 부터 8 KHz까지 주파수별 반사소음차이는 없으나, R3의 경우 63Hz에서 1.3dB(A)가 증가하였고, 8000 Hz에서는 0.5 dB(A)의 소음이 감소하였다. 결론적으로, 방음벽에 형상을 둠에 따라 반사소음 저감효과가 있음을 확인하였으며 최적형상 방음벽을 개발함으로써 반사음 문제해결이 가능할 것으로 사료된다.

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.