• Journal of the Korean GEO-environmental Society
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• v.25 no.4
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• pp.5-12
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• 2024

In the case of creating a site in the reclaimed land (public waters), due to the nature of the coastal sedimentary ground, large-scale construction materials are required, It is necessary to utilize soft clay, which is inevitably generated during construction of the complex, as a fill material in terms of resource recycling and economic aspects (reducing the amount of embankment required). In this study, changes in the consolidation characteristics of cut-out disturbed soft clay due to the recycling of soft clay soil were identified, and a consolidation settlement design plan was proposed. Through the results of the consolidation test of the study site, the change in consolidation characteristics (compression index reduction, precede load uncountable) due to disturbance (cutting) was confirmed, the method of calculating (consolidation settlement) the filling clay layer as the composite target layer (consolidation target layer, loading load layer) was analyzed as a result consistent with the actual behavior.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.57-65
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• 2007

Effects on the stiffness of the embankment and sandmat on the construction safety of road embankment was investigated in this study by the numerical experiments using FEM. Two points was mainly focused in this study especially. First the deformation characteristics by the change of the stiffness of sand mat and embankment was investigated by the analyzing the consolidation settlement at the center of the embankment and the lateral displacement at the toe of the embankment. And, the effect of the stiffness on the stress distribution characteristics was also investigated in this study. Furthermore, slope stability analysis was carried out to gain the safe factor by change the stiffness of the sandmat and the embankment. The objective of the study is supplying the result of the numerical experiments for the geotechnical engineers who use the FEM for the safety design of the soil structures. As a result, the stiffness of the superstructures greatly affects on the deformation characteristics both in consolidation settlement and lateral displacement. However, it can be aware that it is not dominants to the stress distribution in the aspect that the no changes in the residual excess pore water pressure. Therefore, the decision of the stiffness has to be carried out deliberately considering not only the consolidation the magnitude of the settlement and the lateral displacement, but the slope stability.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.771-781
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• 1994

The heat generation of cement causes the internal temperature rise and volume change at early age, particulary in massive concrete structures. As the results of the temperature rise and restraint conditions, the thermal stress may induce cracks in concrete. Therefore, the prediction of the thermal stress is very important in the design and construction in order to control the cracks developed in mass concrete. In case of young concrete, creep effect by the temperature load is larger than that of old concrete. Thus, the effect of creep must be considered for checking the cracks, serviceability, durability and leakage. This paper is concentrated on the development of a finite element program which is capable of simulating the temperature history and the thermal stress considering creep and the modified elastic modulus due to inner temperature change and maturity. The analytical results in the inner parts highest important to control cracks are in good agreement with experimental data. Therefore this study may provide available method to control the cracks.

• Journal of the Korean Society of Costume
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• v.60 no.7
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• pp.88-102
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• 2010

The research examines the characteristics of the sewing methods used for women's Jeogori in modern Korea. The results are following. In the 1920s sewing of shoulder parts was started, and in the 1930s sewing by hand had reduced by dissemination of sewing-machine, and in the 1940s the Som-jeogori declined by the matter of economic and sanitary issues. In the 1950s four-fold sewing emerged, and during the 1960s the gause-lined triple-layered Jeogori was in fashion, and in the 1970s the Ggaeggi-jeogori and much elaborated Jeogori became in vogue. The characteristics of the sewing methods are changed by following factors. First, the dissemination of sewing-machine in the 1930's enabled fast and precise sewing of Jeogori which reduced the rate of clothes mending and the production period. Second, by development of washing method, the dry cleaning became common, resulting cleaner washing and better preservation. Third, introduction of western clothes gave rise to modernized Han-bok which was changed into practical and simple one. Fourth, by the introduction of synthetic textile and industry development, Jeogori with no armhole line or right Seop line was made using wide selection of textiles. Fifth, in 1945~60s, women learned' good wife and wise mother' education and the use of sewing machine in school. The clothing lifestyle affected the sewing method's change, for example, clothes sewed strongly by sewing machine not to take clothes apart, and attaching button instead of Go-reum to save clothes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.94-102
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• 2013

In this study, numerical modeling was performed to investigate influence of the apron shape on the discharge performance of the sluice for tidal power plant. The numerical modeling was carried out for comparison of the difference in the discharge coefficient when the apron width, slope, and the length of the horizontal section were different, without considering change in the shape of the sluice caisson itself. The modeling result showed that significant discrepancy in terms of the overall discharge performance appeared according to the apron geometry. In order to achieve maximum discharge performance of the sluice caisson, it is desirable to make the design by putting a space equivalent to the width of the sluice caisson on its both sides, by making the apron slope be 1:5, and by keeping length of the horizontal section to be 50 m that is corresponding to the streamwise length of the sluice caisson.

• Tunnel and Underground Space
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• v.20 no.1
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• pp.58-64
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• 2010

GLI model was verified to consider the interaction between a ground and a tunnel lining and to rationally reduce the ground load acting on the secondary lining(concrete lining) of a tunnel. In this study, the economy and the construction condition of tunnel concrete linings designed by a conventional frame model at Lot O of OO line were highly enhanced through a field design change using GLI model. For a few safe considerations, not only about 50% saving of reinforcing steel could reduce the material cost but also the wide space between bars could make it easy to pour concrete mix without voids. There was large saving effect of reinforcing steel for poor ground conditions because Terzaghi's load used in the conventional frame model produces too much high loads for those conditions.

• Journal of the Korean housing association
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• v.28 no.1
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• pp.37-44
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• 2017

This study focuses on the university dormitory remodeled toward energy efficiency. The study has its purpose on deriving the aspects to be concerned for later green remodeling and enhancing the effects of green remodeling, by analyzing the changes of physical environment, changes of energy consumption amount, and needs of the residents. For this purpose, the study went through the review of project report from government office for green remodeling, field investigation of remodeling elements, and the occupancy evaluation by Focus Group Interview. FGI means interviewing small group of the residents who lived in the subjected dormitories both before and after the remodeling. As results, the elements of green remodeling in targeted dormitories were inner wall insulation, top-floor ceiling insulation, replacement of windows, installment of automatic entrance door and making transfer space connected the entrance door. As the parts of equipment system, EHP high-efficiency cooler, highly efficient radiator, upgraded LED lightings with covers, and automatic control system (only one building) were installed. Energy consumption was declined, and the satisfaction of residents was increased after the green remodeling. However, the aspects which were not improved or unsatisfying also have been detected. Therefore, the study states the suggestions each for the administrators, designers and planners, and residents to concern for enhancing the effects of green remodeling or construction of new dormitories.

• Smart Structures and Systems
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• v.17 no.1
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• pp.73-89
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• 2016

The stress dependence of ultrasonic wave velocity is known as the acoustoelastic effect. This effect is useful for stress monitoring if the acoustoelastic coefficient of a subject medium is known. The acoustoelastic coefficients of metallic materials such as steel have been studied widely. However, the acoustoelastic coefficient of concrete has not been well understood yet. Basic constituents of concrete are water, cement, and aggregates. The mix proportion of those constituents greatly affects many mechanical and physical properties of concrete and so does the acoustoelastic coefficient of concrete. In this study, influence of the water-cement ratio (w/c ratio) and the fine-coarse aggregates ratio (fa/ta ratio) on the acoustoelastic coefficient of concrete was investigated. The w/c and the fa/ta ratios are important parameters in mix design and affect wave behaviors in concrete. Load-controlled uni-axial compression tests were performed on concrete specimens. Ultrasonic wave measurements were also performed during the compression tests. The stretching coda wave interferometry method was used to obtain the relative velocity change of ultrasonic waves with respect to the stress level of the specimens. From the experimental results, it was found that the w/c ratio greatly affects the acoustoelastic coefficient while the fa/ta ratio does not. The acoustoelastic coefficient increased from $0.003073MPa^{-1}$ to $0.005553MPa^{-1}$ when the w/c ratio was increased from 0.4 to 0.5. On the other hand, the acoustoelastic coefficient changed in small from $0.003606MPa^{-1}$ to $0.003801MPa^{-1}$ when the fa/ta ratio was increased from 0.3 to 0.5. Finally, it was also found that the relative velocity change has a linear relationship with the stress level of concrete.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.244-244
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• 2015

Managed Aquifer Recharge (MAR) in the form of Aquifer Storage and Recovery (ASR) systems are being applied for numerous water augmentation projects both in developed and developing countries. Given the onset of Climate Change and its influence on weather patterns and land use, it has been acknowledged the utilization of this technology will be ever increasing. This technique like all others does have its drawbacks or disadvantages, whereby to overcome these drawbacks or disadvantages it is recommended that logical planning process be followed. In this study, we developed a decision framework known as "Decision framework for the planning, designing, construction/testing and implementation of subsurface water storage system" to further standardize the planning and design process of subsurface water storage system to increase the probability of having a successful ASR/ASTR project. The formulation of this framework was based on earlier frameworks, guidelines, published papers and technical reports which were compiled into a data collection database. The database of which consider both qualitative and quantitative aspect for example recharge objectives, site location, water chemistry of the native, source and recovered water, aquifer characteristics(hydraulic conductivity, transmissivity, porosity), injection/pumping rate, ecological constraints, societal restrictions, regulatory restrictions etc. The assimilation of these factors into a singular framework will benefit the broad spectrum of stakeholder as it maps the chronological order under which ASR project should be undertaken highlighting at each stage the feasibility of the project. The final stage of which should result in fully operational ASR system. The framework was applied to two case studies and through the application of a modified ASR site selection suitability index (Brown et al., 2005) a score was derived to identify the performance of each site. A high score of which meant a maximize chance of success given the reduce presence of project constraints.

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