• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.411-417
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• 2010

The Seoul metropolitan government has installed soundproofing walls in road tunnels to improve the tunnel environment for pedestrians. To evaluate the efficiency of these soundproofing walls, we measured noise levels and concentrations of $PM_{2.5}$ and ultrafine particles (UFP) in tunnels with or without these walls. Although noise and UFP levels were significantly lower in the tunnels with soundproofing walls, $PM_{2.5}$ levels were significantly higher: but were significantly lowered by use of a ventilation system. When $PM_{2.5}$ and noise levels were simultaneously measured in a tunnel with soundproofing wall, noise level was significantly reduced but $PM_{2.5}$ level was significantly higher. It is concluded that the soundproofing wall can protect pedestrians from noise, but not PM. Installation of a ventilation system is recommended for protection of pedestrians in tunnels with soundproofing walls.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.2
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• pp.120-125
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• 2015

With rapid urbanization, the volume of traffic in urban area has been significantly increased. This in turn led to problem which can be described as Road Traffic Noise. Currently, to alleviate the road traffic noise damage, a demand for installation of soundproofing walls is rising. Among different shapes of soundproof walls being installed, the reflection-type acoustical insulation panel is highly drawing attentions of residents due to the fact that it does not obstruct their field of vision in contrast with the opaque acoustical insulation panel. On the other hand, improving the soundproofing wall of the reflection-type acoustical insulation barrier panel needs to be focused on since it has a possibility to cause a secondary damage by reflected sounds. Therefore, in this research, study has been carried out to improve the forms in order to minimize travelling of reflected sounds through changing the frontal surface shape and geometrical shape of the reflection-type soundproofing panel. A result from comparison between the normal reflection-type soundproofing panel and the improved soundproofing panel, with reduction effects in the noise reflection, showed that the curved type of soundproofing panel has an impact on reducing the noise up to 1.5 dB. Furthermore, from the research conducted, it appears that the increase and decrease in the reflected sounds can be changeable depending on various design factors. Thus, it turns out that the study shows a potential possibility to develop a reduction technology of the reflected sounds pertaining to overall condition on the soundproofing walls.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2258-2270
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• 2008

After rapid running is begun in domestic, problem by the train wind that was not considered at existent train running appeared. If the High-Speed railway business speed rises by 350km/h in the future, is going to become more big issue. This study conducts an experiment that measure in local about KTX train beside Gyeongbu High-Speed railway track about aerodynamics effect that happen by passage of train and analyzed. In case KTX II runs with the 350km/h speed, forecasted effect that get in the simple vertical surfaces parallel to tracks according to distance from rail center. Compared construction size with structural analysis in case do not consider with case that consider the train wind about soundproofing walls representatively. As a result, proposed wind load standard that apply at soundproofing walls design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.2
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• pp.191-196
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• 2016

Applying diffraction of waves and muffler principle, the theory of macroscopic air ventilation with soundproofing was explained. Soundproofing frequency range can be selected by this method. The sound wave was attenuated at the resonator located between double-layered walls. A soundproof plate was designed and the experiment was processed. There are two air holes of diameter of 5cm and thickness of 8cm on the surfaces per each soundproofing cell. There was a transmission loss of about 25dB and it is more than at least 10dB compared with that of the Comnex technology of wave cancellation by air holes in Japan. Furthermore, there was no soundproof frequency selection in the Comnex technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.272-278
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• 2018

Traffic volume has been greatly increasing due to urban development and the improvement of living standards, and many complaints are being raised due to the increasing road noise. As a countermeasure against these problems, highly soundproof walls are installed on the sides of roads. However, the ability to bear wind loads is a major design requirement for soundproof walls, which contributes to the exponential increases in construction costs and restricts the height of the walls. The aim of this study is to improve the performance of soundproof walls and to dramatically reduce wind loads while maintaining excellent price competitiveness. Based on Helmholz's resonator theory, a new concept is proposed for a ventilation-type soundproofing plate that can pass through a fluid like air and reduce noise. A full-scale metal soundproofing plate was produced to satisfy the quality standards of highways by conducting a sound-pressure transmission-loss test, wind tunnel test, and material quality test. To verify the reliability, the wall was manufactured and installed, and the sound insulation effect was examined by measuring the noise over time. In the future, ventilated soundproof walls on roads could create a pleasant living environment due to the high noise-insulation effect.

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.9-15
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• 2009

This research presents the structural performance and an improving technique for flexural capacity of road safety facilities based on the damage cases by wind pressure. Among road safety facilities, a support frame of soundproofing walls is considered as a prototype structure and its corresponding structural behaviors and section design are performed mainly by analytical and experimental studies. On the basis of analytical results, glass fiber reinforced polymer(GFRP) with an epoxy matrix which is high stiffness-to-weight ratio was used for applied one of strengthening techniques and their results shows that support frame strengthened by GFRP is the most effective compared to other cases proposed in this research for advancing its flexural improvement, Finally, optimum section design was performed analytically to evaluate wind-resistance capacity and its result would be very useful for developing a practical design guideline for Road safety facilities under strong wind.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.152-160
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• 2023

Sound barrier walls are the most basic way to cope with noise problems in urban residential environments. The most important acoustic function of sound insulation board is represented by sound transmission loss and sound absorption coefficient. However, Korea has not yet established a standard for measuring the sound absorption rate of sound insulation boards. In addition, even in the European standard, where the overall acoustic standard of soundproofing boards has already been established, the sound absorption rate is applied only to the standard for measuring the sound absorption rate of general building finishing materials, and a separate measurement method considering the characteristics of soundproof walls and soundproofing boards is not presented. The sound absorption coefficient should be evaluated by summing up the energy absorbed into the material as well as the energy transmitted through the material, but the current European standard has a problem in that the transmitted sound energy is not taken into account. In this paper, we reviewed the sound absorption coefficient measurement standards of sound insulation boards currently being presented, and verified the difference between the results and the new measurement method considering transmission sound for sound insulation boards actually used in Korea.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1048-1052
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• 2007

Using road traffic noise, noise map for CheongJu city was drawn. Noise level is estimated and many regions of the city are classified noise excess area compared with environment standard value. Counterplan for the noise excess areas is presented in this study. Noise reduction methods are given in many ways, for example soundproofing walls, low noise pavement, low noise arrangement of buildings and low noise windows.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.52-57
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• 2003

This study suggests several ways to improve the railroad facilities in the urban areas so as to maintain the urban railroad facilities and minimize their adverse impact on the roads around the facilities. Environmental problems such as noise and vibration can be minimized by constructing soundproofing walls and improving railway and train systems. To reduce the traffic congestion at the railroad crossings, current at-grade crossings should be changed to separated crossings. Moreover, the criteria by where railroad crossings are located should be revised. In the long term, the land use development for the railroad station and the surrounding areas needs to be changed. Several case studies of Japan's and France's major cities show the potential of successfully integrating the development of railroad facilities and their surrounding areas. In addition, there is a need to .consider institutional aspects, to improve the railroad facilities in the urban areas and to allow the integrated development of the railroad facilities and the surrounding areas.

• Journal of the Korean housing association
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• v.15 no.5
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• pp.33-41
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• 2004

This study examined the effect of the main color of apartment building as background color on the preference for residential streetscape in the relation with surrounding environment of streetscape with its focus on the color of apartment building outer wall. To research a visual evaluation structure, this study aimed to understand its characteristics through quantitative assay and to provide more scientific and specific data about improvement direction. The results suggested that the current brightness and chroma of main color of apartment building was high and low respectively which was advisable. On the other hand, in the color, when the components of the whole streetscape included buildings or soundproofing walls, a streetscape image needed to be improved though the color scheme of 4-distance color difference.