• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.1
• /
• pp.25-32
• /
• 2019

The urban river has played an important role in biodiversity by providing various waterside areas in urban areas that are difficult for organisms to live in. The river is also used as a resting place and experience space for citizens. In particular, Yeouido Saetgang is the first ecological park in Korea, and it is located in the heart of downtown Seoul, making it highly valuable for its location and ecological value. However, water quality issues have continuously been raised since the construction project of Yeouido Saetgang river. So it is necessary to investigate the environment state and analyze the causes of the environment deterioration. In this study, the causes of the river stagnation and water quality deterioration in Yeouido Saetgang river were analyzed. For this, river surveys and aerial photo analysis were used to analyze the causes of difficulties in natural water circulation. Also, the results of monitoring water quality showed that the averaged level of BOD and T-P in dry season is III and IV, respectively, while that of BOD and T-P are V~VI in rainy season. In addition, through the drainage analysis of sewer network, small drainages that affect the water quality in Saetgang river was selected and discussed.

• Journal of Korean Society of Disaster and Security
• /
• v.11 no.2
• /
• pp.17-28
• /
• 2018

The purpose of this study is to investigate the effect of underground facilities around excavation zone on groundwater flow characteristics during excavation. The scenarios were constructed considering the size of the underground facility, the separation distance, and the hydraulic gradient. As a result, as the size of the underground facility increases, the difference of head and the hydraulic gradient become large. The shorter the separation distance of underground facility is, the more the difference of head and the hydraulic gradient occur. The effect of hydraulic gradient on model area was relatively small. As a result of analysis of groundwater flow rate for the scenario, groundwater flow rate tends to decrease as the size of underground facility increases or groundwater flow rate tends to decrease as the separation distance decreases. It is necessary to examine the effect of underground facilities on the groundwater flow analysis in the ground excavation.

• Wind and Structures
• /
• v.29 no.4
• /
• pp.235-246
• /
• 2019

Wind loading is one of important loadings that should be considered in the design of large hyperbolic natural-draught cooling towers. Both external and internal surfaces of cooling tower are under the action of wind loading for cooling circulating water. In the previous studies, the wind loads on the external surface attracted concernedly attention, while the study on the internal surface was relatively ware. In the present study, the wind pressure on the internal surface of a 220 m high cooling tower is measured through wind tunnel testing, and the effect of ventilation rate of the packing layer on internal pressure is a major concern. The characteristics of internal wind pressure distribution and its effect on wind-induced responses calculated by finite element method are investigated. The results indicate that the wind loading on internal surface of the cooling tower behaves remarkable three-dimensional effect, and the pressure coefficient varies along both of height and circumferential directions. The non-uniformity is particularly strong during the construction stage. Analysis results of the effect of internal pressure on wind-induced responses show that the size and distribution characteristics of internal pressure will have some influence on wind-induced response, however, the outer pressure plays a dominant role in the wind-induced response of cooling tower, and the contribution of internal pressure to the response is small.

• Explosives and Blasting
• /
• v.36 no.4
• /
• pp.48-61
• /
• 2018

This case study is concerned with the project of the explosive demolition for the KOGAS office building located in Bundang district in Seongnam city. Since the office building was a kind of long-span beam structures, a mechanical demolition method using jacking support systems was considered in the beginning of the project. With consideration of the excessive reinforcement cost, uncertainty of safety, and prolonged construction period, however, the original plan was later changed to use an explosive demolition method. For the purpose of protecting nearby buildings and facilities during the collapse process, the explosive initiation sequence was elaborately designed to bring down the building structure towards its front left corner. A total of over 550 electronic detonators (Unitronic 600) was used to sequentially initiate the explosives installed at appropriate columns in the first, second, and fifth floors. To diminish dust production, water bags of small and large sizes were respectively installed at each column and on the floors to be blasted. As such, every effort was exercised to mitigate overall noise, dust, and shock vibrations that could be generated during the explosive demolition process for the office building.

• Computers and Concrete
• /
• v.23 no.1
• /
• pp.61-68
• /
• 2019

This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature.

• The Journal of the Acoustical Society of Korea
• /
• v.38 no.3
• /
• pp.266-274
• /
• 2019

As can be seen in the statistics on domestic performance facilities, small or large scale of acoustic renovations seem to be unavoidable in many of those facilities due to its senility. However it is hard to find case studies which can be referred to for its acoustic renovation process. This study tried to provide a case study example of acoustic renovation for a high school auditorium which has many restrictions as a cultural heritage building. Requirements from the client and acoustic problems found through a field measurement of existing space motivated acoustic design solutions and alternatives which can improve the acoustics of the space. The whole process from the initial stage of diagnosing acoustic problems to the final stage of a post acoustic evaluation after the completion of construction was described. The result from the post acoustic evaluation suggested that reverberation characteristics of the space as well as definition and clarity have been greatly improved by applying acoustic design solutions and alternatives. However, loudness of sounds in the space didn't reach the aimed level, which is due to the limited capability of slat ceiling structure for providing strong early reflections.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.12
• /
• pp.85-94
• /
• 2018

The purpose of this paper was to propose a model that recognizes potential users' emotional response toward design by classifying Electroencephalography(EEG). Studies in neuroscience and psychology have made an effort to recognize subjects' emotional response by analyzing EEG data. And this approach has been adopted in design since it is critical to monitor users' subjective response in the preface of design. Moreover, the building design process cannot be reversed after construction, recognizing clients' affection toward design alternatives plays important role. An experiment was conducted to record subjects' EEG data while they view their most/least liked images of small-house designs selected by them among the eight given images. After the recording, a subjective questionnaire, PANAS, was distributed to the subjects in order to describe their own affection score in quantitative way. Google TensorFlow was used to build and train the model. Dataset for model training and testing consist of feature columns for recorded EEG data and labels for the questionnaire results. After training and testing, the measured accuracy of the model was 0.975 which was higher than the other machine learning based classification methods. The proposed model may suggest one quantitative way of evaluating design alternatives. In addition, this method may support designer while designing the facilities for people like disabled or children who are not able to express their own feelings toward alternatives.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.2
• /
• pp.43-52
• /
• 2019

The purpose of this study is to classify the building layout and plan types according to the urban location, use and function of civil and to analyze the characteristics by the type classified. After constructing a framework (Mathia type, Nagaya type, Detached House type) for analyzing Modern Private Housing Architecture in Gunsan, the research was conducted on 30 representative buildings, and a plot plan, a floor plan and elevation were created. After analyzing the relationship between the lot of land and the urban street, we classified the type of arrangement into Mathia type and Nagaya type which directly enter the building from the road, and derived the Detached House type which indirectly enters from the road. When we look at the use of the derived arrangement types, most of the Mathia type are commercial and residential buildings, and some of them are specially designed for commercial buildings. The Nagaya type appears in the form of commercial and residential house or residential private house, and the Detached House type is classified as residential style. As a relation with the urban street, the Mathia type and the Nagaya type are generally located on the main urban street, whereas the Detached House type is located on the small urban street. As a result of analyzing, the floor plan was changed according to the plot plan. The plan of the Mathia and Nagaya type are arranged to enter directly from the street, with commercial space being mainly located on the street, and the residential space being composed on the back or the second floor. the plan of the Detached House is a type that enters indirectly into the interior through a separate space (Courtyard), and forms an organic space between the residential interior and the front and rear yard. The purpose of this study is to investigate the Characteristics of a plot plan and a floor plan of Modern Private Housing Architecture in Gunsan by means of analysis considering the urban street, Uses of buildings, Construction method and the yard through actual measurement.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.12
• /
• pp.145-156
• /
• 2018

This study explores changes of industrial scales and building activities in the semi-industrial area of Seoul's Seong-su, responding to the shifts of industrial structures and policies in the Korean society. The purpose of this study is to investigate patterns of construction activities of factory buildings in the Seong-su semi-industrial area by analyzing changes in industrial facilities. As a result of the analysis, the change of the factory building area come out from the recent survey implies the possibility of entrepreneurial inflow as much and the new constructions and some remodeling cases which are characterized by complexity seem to correspond to the industrial structure. However, it is unreasonable to believe that this phenomenon is a mainstream movement involving small-scale factory buildings and companies. This is because there are aspects that are not included in this movement, such as changing the use of buildings without accompanying physical changes. On the other hand, compared to various movements of individual companies in response to the industrial structure, the physical plan suggests a limited alternative centering on the floor area ratio and the building area ratio. This means that the efforts to attract and grow the power of knowledge based-industry through the designation of the Industrial Development Promotion District in part of the case sites, overlook the natural change through remodeling and reuse of existing buildings. In addition, considering the fact that the production space of industrial use can be greatly influenced by the behavior of users compared to general buildings such as residential and commercial, it is necessary to pay attention to various phenomena occurring in the area more locally than the uniform supply policy. Based on these findings, this study contributes to illuminate the legal system related to building act in the Seong-su semi-industrial area and the potential direction of architectural suggestions in related policies and researches.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.1
• /
• pp.93-98
• /
• 2019

Recently, the rise in the housing burden on young couples has led to a serious housing poverty among young people. The number of young people who move into public rental housing is very small because the eligibility for public rental housing is determined based on income, the status of housing subscription, and the size of the household. With this background, the government launched a public rental housing program called Happy Housing Project, which gives young people the priority to move in first. However, the program is facing an obstacle due to the opposition of local residents. The purpose of this paper is to examine whether public rental housing can induce the NIMBY syndrome through conducting a literature review, followed by an analysis of NIMBY syndrome around the currently supplied Happy House development areas, and finally analyzing the household characteristics in order to identify which households were prone to the NIMBY syndrome. To confirm the existence of the NIMBY syndrome, this paper comparatively analyzed the two groups using binary logit analysis. The first group consists of households that are against the Happy House policy, and the second group consists of households that are aware of the Happy House development taking place in their neighborhoods, and are against the development. This study considered the households against the Happy House development in their neighborhoods to have NIMBY tendencies, and focused on comparing the households with NIMBY tendencies with those who do not. To confirm whether the residents around the Happy House neighborhoods have NIMBY tendencies, this paper compared the two groups and confirmed that about 4% of the households have NIMBY tendencies. This paper subsequently analyzed the households with NIMBY tendencies, and found them to have a higher number of children, reside in apartments and reside in owned homes. The volume of the 2018 Happy Housing (35,000 households) is three times higher than that of 2017. The present study aims to analyze the tendency of residents who oppose the construction of Happy Housing so as to derive policy implications for the smooth provision of public rental housing.