• International Journal of High-Rise Buildings
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• v.9 no.2
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• pp.197-212
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• 2020

In this study, POE(Post Occupancy Evaluation) evaluation indexes were selected into six categories through the consideration of theories and prior research. Therefore, qualitative supply can be achieved through POE according to the aspect of residential environment after the quantitative supply of mixed-use apartment complex by the population concentration in Seoul due to industrialization and urbanization. As the evaluation elements, detailed survey contents were selected for livability, convenience, comfort, safety, economy, and sociality. Based on the survey contents, six elements were evaluated and analyzed using Data coding and Likert scale after surveying 12 complexes (Urban areas and non-urban areas) in Seoul. As a result of the study, six categories selected as the POE showed that importance of quality of life and safety was developed in high recognition according to high satisfaction with convenience and safety. Sociality showed the lowest satisfaction in the following order : livability, comfort, economy and sociality. Residents' sense of community, interaction with neighborhood, etc., showed low satisfaction, and it seems that it is necessary to improve and supplement the system for the development of mixed-use apartment complex in the future. The detailed characteristics of livability showed high satisfaction of the living room, the front door and the main room which are main uses of housing, and low satisfaction in storage size. The analysis of convenience is that convenient public transportation was the highest, and educational environment and additional facilities were the lowest, showing the advantages and disadvantages of location characteristics. As a result of the analysis of comfort, satisfaction with the landscape area was low and it seems that green space is needed for the development of mixed-use apartment complex in the future. Lastly, regarding the safety, the satisfaction of the access control, the location of security office, etc. were high, however separation of circulation was low. Therefore, it is necessary to clearly separate the circulation between the residence and other facilities in the mixed-use apartment complex.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.987-996
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• 2015

According to the recent research results of the Ministry of Environment, the indoor air quality of large general hospitals and university hospitals(58 hospitals) exceeded the maintenance standard. On top of such indoor air quality, it is also desperately required to have the environment-friendly building design and also low carbon green design in accordance with the increase of hospital size and enlarged hospital buildings. Especially, the increase of carbon dioxide, heat, garbage, waste energy, exhaust heat from power plants and sewage heat in each medical center brings up lots of problems to the health of hospital patients and customers. Thus this study aims to convergently develop the green environment-friendly architecture design technology concerning the organic relations between each medical building, and technical development which should be introduced to the low carbon green environment-friendly architecture design based on the characteristics of each medical center in large-scale medical complex.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.2
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• pp.52-62
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• 2015

This study aims at developing a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were performed on one unreinforced beam-column specimen and two reinforced specimens with U-type precast wall panels. Top shear connection of the PC panel was required to show the composite strength of RC column and PC wall panel. However, the strength of the connection did not influence directly on the ultimate loading capacities of the specimens in the positive loading because the loaded RC column push the side of PC wall panel and it moved horizontally before the shear connector receive the concentrated shear force in the positive loading process. Under the positive loading sequence(push loading), the reinforced concrete column and PC panel showed flexural strength which is larger than 97% of the composite section because of the rigid binding at the top of precast panel. Similar load-deformation relationship and ultimated horizontal load capacities were shown in the test of PR1-LA and PR1-LP specimens because they have same section dimension and detail at the flexural critical section. An average of 4.7 times increase in the positive maximum loading(average 967kN) and 2.7 times increase in the negative maximum loading(average 592.5kN) had resulted from the test of seismic resistant specimens with anchored and welded steel plate connections than that of unreinforced beam-column specimen. The maximum drift ratios were also shown between 1.0% and 1.4%.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.415-425
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• 2016

Load-bearing steel stud wall system is widely used for the middle-to-high rise modular buildings worldwide. Seismic performance is a key issue to apply load-bearing steel stud wall system to modular buildings in Korea. This study proposes a new strap braced steel stud wall system with enhanced seismic performance and design equations considering the flexural behaviour of the vertical outer studs. For the verification, two specimens with different strap braces and vertical outer stud were designed and tested. The test results showed that the total strengths were evaluated to be 1.11 to 1.18 times higher than the predicted values. Usually strap braced walls are considered to have low energy dissipation capacities. The proposed system showed enhanced seismic performance with equivalent damping of 9.42% due to the reduced pinching effects.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.55-63
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• 2013

In this study, seismic performance was evaluated considering the deterioration level for the low-rise and moderate buildings with non-seismic details which are most common in Korea. Evaluation results showed that the deterioration condition is relatively good even after 24 years of construction but the seismic performance did not satisfy the protection index in the first and second evaluation. In case of the third evaluation, the goal performance was satisfied based on the interstory drift ratio but reinforcement is found to be necessary. Seismic performance was evaluated after the target buildings were reinforced in the walls, bracing, and damper. Results showed the interstory drift ratio drastically reduced regardless of reinforcement methods and satisfied the level of immediate occupancy. In case of wall reinforcement, however, base shear increased more than double which requires review on the existing foundation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.1-9
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• 2014

Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. In this study, a non-compression cross-bracing system using the Carbon Fiber Composite Cable (CFCC), which consists of CFCC bracing and bolt connection was proposed to replace the conventional steel bracing. This paper presented the seismic resistance of a reinforced concrete frame strengthened using CFCC X-bracing. Cyclic loading tests were carried out, and the maximum load carrying capacity and ductility were investigated, together with hysteresis of the lateral load-drift relations. Test results revealed that the CFCC X-bracing system installed RC frames enhanced markedly the strength capacity and no buckling failure of the bracing was observed.

• Journal of the Korean Institute of Educational Facilities
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• v.25 no.4
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• pp.11-18
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• 2018

Global warming is happening now and inevitable. Everyone knows that immediate action should be taken to slow it down, but uncertain about the effective solution. Despite global efforts to reduce greenhouse gas emissions, sea levels are rising gradually. In 2013, Cornell University announced the Climate Action Plan(CAP) to make the campus greener, to reduce waste, and to ensure efficient use of resources. In particular, they set a goal of reducing energy use by 2050 and making carbon emissions to zero. Accordingly, the purpose of this study is to analyse the case of the master plan of Cornell Tech campus and its major buildings. Mainly, The House, faculty and student housing of Cornell Tech and the world tallest certified passive house, will be the main precedent that shows the architectural planning of passive house. Passive house technology, which was thought to be possible only in single-family houses, can be applied to high-rise buildings. If any passive house technology of The House project is actively introduced into the dormitory projects of domestic universities that are about to be built or renovated, it will be a good opportunity for the university to take the lead in preparing for global warming.

• Journal of the Korean housing association
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• v.20 no.6
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• pp.1-10
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• 2009

Rapid social change affects residential environments and this in turn creates new stimuli to which people have to adapt. These stimuli have been seen to increase stress levels. Therefore, dwellers in these environments try to reduce stress through various methods. The purpose of this paper is to: 1) identify the general trends of coping styles about residential environmental stress, 2) analyze the differences in socio-demographic characteristics and how the physical characteristics of buildings affect stress, find out how personal backgrounds affect stress levels and the ability to get rid of environmental-related stress. The subjects in this study consisted of people living in multi-family housing in Gwangju. The city is divided into 5 districts and used quota sampling. 324 housewives were surveyed from the households by self-administered questionnaires. The survey was conducted in December, 2006, after the questionnaire was revised based on the results of preliminary survey. After all the questionnaires were collected, the data was coded and analyzed using the SPSS 12.0 program. This study confirmed that the manner in which those in multi-family housing coped with stress. Especially, we need a policy which seriously considers residents who are of low social-economic standing. As well as being exposed to residential environmental stress, they also have no means to deal with it. The age of a building had a strong impact on coping styles about residential environmental stress. We have to make special studies about the adaptive reuse of buildings for the reduction of residential environmental stress and to greatly improve coping styles. In conclusion, it emphasized the importance of education, information, and economic aid. Reasonable housing management would surely lead to a rise in residential satisfaction and the promotion of residential welfare.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.3
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• pp.159-167
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• 2019

2016 Gyeongju and 2017 Pohang earthquakes led Koreans to acknowledge that the Korean peninsula is not an earthquake-free zone anymore. Among various buildings crucial to after-shock recovery, general hospital buildings, especially existing old ones, are very significant so seismic retrofitting of those must be an important issue. Self-centering energy dissipative(SCED) brace is one of retrofitting methods, which consists of tendon with restoring force and friction device capable of dissipating seismic energy. The strength of the SCED brace is that the tendon forces a structure to go back to the original position, which means residual drift can be negligible. The residual drift is a very important parameter to determine usableness of general hospitals after shock. To the contrary, buckling-restrained braces(BRB) are also a very effective way to retrofit because they can resist both compressive and tensile, but residual drift may exist when the steel core yields. On this background, the seismic retrofitting effect of general hospitals reinforced with SCED braces was investigated and compared to that of the BRD in this study. As a result, although the floor acceleration cannot be reduced, the story drift and residual drift, and the shear demand of walls significantly decreased. Consequently, seismic retrofitting by SCED braces are very effective for domestic low-rise general hospitals.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.1
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• pp.47-57
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• 2024

Recently, in newly constructed apartment buildings, the exterior wall structures have been characterized by thinness, having various openings, and a significantly low reinforcement ratio. In this study, a nonlinear finite element analysis was performed to investigate the crack damage characteristics of the exterior wall structure. The limited analysis models for a 10-story exterior wall were constructed based on the prototype apartment building, and nonlinear static analysis (push-over analysis) was performed. Based on the finite element (FE) analysis model, the parametric study was conducted to investigate the effects of various design parameters on the strength and crack width of the exterior walls. As the parameters, the vertical reinforcement ratio and horizontal reinforcement ratio of the wall, as well as the uniformly distributed longitudinal reinforcement ratio and shear reinforcement ratio of the connection beam, were addressed. The analysis results showed that the strength and deformation capacity of the prototype exterior walls were limited by the failure of the connection beam prior to the flexural yielding of the walls. Thus, the increase of wall reinforcement limitedly affected the failure modes, peak strengths, and crack damages. On the other hand, when the reinforcement ratio of the connection beams was increased, the peak strength was increased due to the increase in the load-carrying capacity of the connection beams. Further, the crack damage index decreased as the reinforcement ratio of the connection beam increased. In particular, it was more effective to increase the uniformly distributed longitudinal reinforcement ratio in the connection beams to decrease the crack damage of the coupling beams, regardless of the type of the prototype exterior walls.