• Geomechanics and Engineering
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• v.28 no.1
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• pp.1-10
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• 2022

In Korea, accidents related to the collapse of deteriorated aging reservoirs occur every year. The grouting method is generally applied to reinforce an aging reservoir. However, when using this method, different reinforcing effects appear depending on the ground conditions. Thus, new construction methods and materials capable of providing consistent reinforcing effects are required. In this study, the direct shear test (DST), model test, and simulation analysis were performed to evaluate the impact of surface stabilizers, generally used to reinforce roads, rivers, and slopes of roads, applied using surface curtain walls on aging reservoirs. The DST results indicate that when the surface stabilizer was mixed with in-situ soil, the increase in cohesion was the highest at a mixing ratio of 9%. No changes in the friction angle were evident; therefore, 9% was determined to be the optimal mixing ratio. In addition, the model test and simulation analysis showed that when 9% of the surface stabilizer was mixed and applied to the aging reservoir, the seepage quantity of water and the saturated area were reduced by approximately 42% and 73%, respectively. Moreover, the comprehensive analysis of results showed that the grouting method could be completely replaced by surface stabilizers applied through surface curtain walls because the technique could secure stability by decreasing the seepage in the aging reservoir.

• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.26-31
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• 2021

Buildings with glass curtain walls have become popular due to their appealing aesthetics and ability to let in natural light. However, light reflection from the glass surface is unavoidable in these buildings. In particular, the reflection of light from the glass envelope can create afterimage glare, a hazard to nearby drivers and pedestrians. Despite this potential danger, glare from buildings with curtain walls has not been well-studied. Hence, we analyzed the effect of light reflection on glare around a glass-enclosed skyscraper, depending on its surface reflectance. We investigated the potential hazard of glare to drivers using a commercially available software program. The results indicate that the direction of light reflection is distinctive when the incident angle of solar light increases. Moreover, this light reflection is high enough to induce an afterimage to drivers and pedestrians near the building. We found that keeping the reflectance of the building surface under 3% is required to minimize the afterimage hazard to drivers. Consequently, we recommend managing glass reflectance and installing additional traffic safety systems to reduce traffic accidents near curtain wall buildings.

• Journal of the Korea Construction Safety Engineering Association
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• s.41
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• pp.88-101
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• 2007

Recently, the condensation of walls often occurring in domestic high-rise apartment buildings is an important problem. The main purpose of this study is to develop the prediction method for the surface condensation on curtain wall in high-rise apartment buildings. Therefore, in this study, we first analyzed exterior climate factors through the analysis of the Seoul climate data and predicted the change of indoor temperature by using Apache program to find the cause of the condensation state and to prevent condensation. Also, according to this result, exterior climate factors and interior factors, which caused the condensation, was examined. The thermal performance of the curtain wall and the range of potential condensation were analyzed to focus on high-rise apartment buildings through computer simulation programs. The results are as $follows;^1$) The frame edge of curtain wall has a higher U-value than in the center by $30%^2$) Because of stack effect, the rooms on the higher floor have a lower external ventilation rate resulting to a higher relative humidity3) Installing a ventilation system($20m^3$/h. person) makes it possible to have a higher external ventilation rate, resulting to a lower relative humidity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.220-221
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• 2013

Exterior walls are designed and constructed through design focused exterior wall system. Nowadays, freeform facade design has been changing according to material, form and function of the exterior wall system. Especially, curtain wall facade system is designed and manufactured using solar shading faces. However, the traditional method have a lot of difficulties in the currently performing technology for curtain wall facade. It is important to make the freeform facade components that integrated as a surface of freeform buildings. Therefore it is necessary to develop unit module construction method for freeform facade.

• KIEAE Journal
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• v.6 no.1
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• pp.25-32
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• 2006

Regarding to the Domestic housing politics to improve residing environment and effective use of country land, apartment buildings have been constructed since early of 1970s. Now apartment is taking over 50% out of entire housing in Korea. In the view point of PV application to the apartment, PV has amny advantages because of the wideness of out-walls and high floors building in APT. Therefore, if APT could use the electricity produced by BIPV, we can solve more easily environment and energy problems caused by housing. The research conclusion by analysing conditions and application method to introduce BIPV application to APT in near future is as below. -The out look of APT has been developed periodically and recently gable roof or canopy is popular which PV installation is more favorable. -For Balcony part with double skin facade sassy window, It has a preferable condition to install on the wall depending on the window direction. -In case of shorter distance between buildings due to high ratio of outside measurement, it is more desirable to install PV on the roof than on the wall of Apartment by considering low solar altitude. -Also depending on the direction of APT building, it is more effective and productive in electricity in the broad surface of side wall of APT. -In case of superhigh floor APT where facade system is mostly double skin facade of curtain wall system, PV module can replace the traditional curtain wall and will reduce architectural materials and obtain various out look design thereof.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.12
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• pp.565-571
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• 2014

Nowadays, to make buildings light weight and aesthetically pleasing, curtain wall structure are commonly used. Therefore, window to wall ratio is increasing, which has caused cooling and heating load in crease in buildings as well. This phenomenon has negative impact from energy point of view. This paper analyzes window and wall convective heat gain when the slat reflectance of external and internal blinds are changed for the better understanding of the fundamentals behind the phenomena. It was observed that, if slat reflectance is increased, window transmitted solar increases and convection heat rate is clearly affected. Among six surfaces including four walls, ceiling and floor, maximum convection heat rate occurs on the south wall in summer. On the other hand, ceiling and floor showed the lowest convection heat gain, since they are shared by adjacent floors.

• KSBB Journal
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• v.29 no.4
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• pp.285-296
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• 2014

Although the problems of the algal blooms have been world-widely observed in freshwater, estuary, and marine throughout the year, it is not yet certain what are the basic causes of such blooms. Consequently, it is very difficult to predict when and where algal blooms occur. The constituents of the Asian dust are in a good agreement with the elements required for the algal growth, which suggests some possible relationship between the algal blooms and the Asian dust. There have been frequently algal blooms in drinking water from rivers or lakes. However, there is no any algal blooms in upwelling waters where the Asian dust cannot penetrate into the soil due to its relatively weak settling velocity (size of particles, $4.5{\pm}1.5{\mu}m$), which implies the possible close relationship of the Asian dust with algal blooms. The present initiative study is thus intended firstly in Korea to illustrate such a relationship by reviewing typical previous studies along with 12 years of weekly iron profiles (2001~2012) and two slant culture experiments with the dissolved Asian dust. The result showed bacterial suspected colonies in the slant culture experiment that are qualitatively in a good agreement with the recent Japanese studies. Since the diatoms require cheap energy (8%) compared to other phytoplankton (100%) to synthesize their cell walls by silicate, the present results can be used to predict algal blooms by diatoms if the concentrations of iron and silicate are available during spring and fall. It can be postulated that the algal blooms occur only if the environmental factors such as light, nutrients, calm water surface layer, temperature, and pH are simultaneously satisfied with the requirements of the micronutrients of mineral ions supplied by the Asian dust as enzymatic cofactors for the rapid bio-synthesis of the macromolecules during algal blooms. Simple eco-friendly methods to regulate the algal blooms are suggested for the initial stage of blooming with limited area: 1) to cover up the water surface with black curtain and inhibit photosynthesis during the day time, 2) to blow air (20.9%) or pure oxygen into the bottom of the water and inhibit rubisco for carbon uptake and nitrate reductase for nitrogen uptake activities in algal growth during the night, 3) to eliminate the resting spores or cysts by suction of bottom sediments as deep as 5 cm to prevent the next year germinations.