• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.991-999
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• 2018

In urban areas, the proportion of railway traffic in public transport is increasing. The congestion situation is repeated as the passengers concentrate on station and transfer facilities and the inconvenience of the passengers is increasing in terms of safety and convenience. Therefore, the importance of estimating the appropriate area of the station has been emphasized. The area estimation formula used in the metropolitan railway stations currently is a partial modification of the area estimation formula of Japan in the 1970s. It does not reflect changes in the social and cultural environment and patterns of passengers. The technical basis for major decision variables is insufficient. Therefore, the theoretical basis of the area estimation formula and the pedestrian environment satisfaction of the design guideline of metropolitan railway stations were analyzed in order to suggest improvement formula. The improved area estimation formula was verified by conducting field surveys on 5 stations of metropolitan railways and 15 stations of urban railways. The existing area estimation formula is LOS E grade for the main space. However, the LOS D grade is implemented when the improved area estimation formula is applied. Based on the results, the design factors for the area estimation formula are suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.725-730
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• 2017

The strength ratio of the main structures of buildings gradually increasing, due to the advances made in analysis and cost saving techniques. In this study, to examine the stability of industry buildings using sandwich panels as roof assemblies, we examine the changes in the moment strength ratio of the main structures caused by increasing the roof load. This study adopts the PEB structure and three H-steel structure as the structural analysis models. In the case where the additional load exceeds about 11% of the roof design load, the strength ratio exceeds 1 for the main structure. In the case where the additional load exceeds about 36%(of the roof design load), the working moment exceeds the plastic moments, which leads to major damage to the structure. This study compares 1) the maximum load according to the purlin spaces, 2) the maximum load by KS, and 3) the maximum load calculated from the test results of the manufacturer.The maximum bearing load of the panels determined by all three methods exceeds the structure failure threshold load of the main structure. This study provides evidence that an unexpected increase in the roof load might cause the whole structure to collapse, due to the failure of the main structural members, before the failure of the roof assemblies. Therefore, information on the structural performance of the sandwich panels is required for the structural design, and the sandwich panels should be considered to be an integral part of the overall structural design.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.516-516
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• 2017

기후변화로 인하여, 홍수, 사막화, 엘니뇨 등의 자연재해가 이전보다 더 발생하고 있다. 기후변화 적응은 전 세계적으로 기후변화 대응보다 중요해지고 있다. 기후변화 적응을 위한 이슈 중 하나가 물 순환이다. 각 국가에서는 물 순환을 활성화하기 위한 기술을 개발하고 있다. 특히, 저영향개발(LID, Low Impact Development)이라는 물을 확보하기 위한 정책이 각 국가별로 추진되고 있으며, 이에 따른 기술이 개발되고 있다. 국내에서도 2001년에 국토해양부는 수자원장기종합계획을 발표하고, 환경부에서는 2013년에 LID기술요소 가이드라인과 환경영향평가 시 적용 가능한 저영향개발 매뉴얼을 개발하는 등 LID기술을 개발하고 적용하기 위한 정책을 펼치고 있다. 이러한 LID기술 중 하나가 빗물 집수시스템이며, 이 빗물집수시스템은 주거지역에서 빗물을 배수하고, 집수하여 빗물을 이용하기 위해 적용되고 있다. 현재 적용되고 있는 빗물 집수시스템은 측구 집수시스템과 원형 집수시스템이 있으며, 최근에는 수로형 집수시스템이 적용되는 지역도 있다. 본 연구에서는 전과정 평가(LCA, Life Cycle Assessment)를 이용하여 빗물 집수시스템의 환경성을 평가하고자 한다. 현재, 국내에서는 녹색건축물인증, 탄소성적 표지인증, 환경성적 표지인증 등 LCA를 이용하여 환경성을 평가하고 있다. 특히, 본 연구에서는 기후변화 측면에서 LCA를 적용하여 이산화탄소배출량을 평가하고자 하였다. 본 연구의 범위는 빗물집수시스템 30m로 가정하였으며, 측구 집수시스템, 원형 집수시스템 및 수로형 집수시스템의 건설, 운영 및 유지관리, 해체 및 폐기단계의 전 과정이다. 각 빗물 집수시스템에 대해 각 단계별로 이산화탄소 배출량을 산정한 결과, 수로형 집수시스템은 $2.82\;ton\;CO_2\;eq./set$이며, 원형 집수시스템은 $27.65\;ton\;CO_2\;eq./set$, 측구 집수시스템은 $21.54\;ton\;CO_2\;eq./set$이 배출되었다. 이산화탄소배출량 측면에서는 수로형 집수시스템이 나머지 두집수시스템보다 87~90%가 저감되는 것으로 나타났다. 본 연구는 저영향개발에 대응하는 동시에 기후변화를 대응한다는 측면에서 빗물 집수시스템 정책에 활용되고, 설계시에도 반영될 수 있을 것으로 사료된다. 추가적으로 이산화탄소뿐 만 아니라, 다른 환경성을 평가하는 연구가 진행될 필요가 있다.

• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.3-14
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• 2021

In the Chinese construction industry, the utilization of Building Information Modeling (BIM) aims to increase the total output of the construction industry by solving the problem of inefficient interoperability in the construction industry. In 2011, the Chinese Ministry of Housing and Urban-Rural Development despite the technical advantages of BIM and the government policy, the BIM adoption rate in China is lower than 45%. Meanwhile, as the South Korean construction industry is a step ahead of its Chinese counterpart in introducing and utilizing BIM, it is expected that BIM is more actively utilized and accepted in South Korea than in China. According to a comparative study based on the hype-cycle theory, South Korea is at a more advanced stage of introducing BIM, than in China. This study aimed to suggest how to increase BIM utilization rates in China. To this end, this study comparatively analyzed factors affecting BIM acceptance between China and South Korea. For the comparative analysis of the BIM acceptance factors between China and South Korea, literature reviews on the technology acceptance model (TAM) and BIM acceptance model were carried out, and based on that, the BIM acceptance factors were classified. Other BIM acceptance factors were also added and considered, as they reflected Chinese national characteristics and construction industry. As for the derived BIM acceptance factors, construction project participants, especially actual BIM users in China and South Korea, were targeted for the survey. A t-test using SPSS 22.00 was carried out to identify significant differences in data. Finally, based on the t-test results, this study suggested ways of improving the BIM utilization rate in China. Based on the findings, this study is expected to contribute to activating BIM adoption in the Chinese construction industry and also to set a theoretical foundation for future studies on BIM utilization in the industry.

• Journal of the Korean Geotechnical Society
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• v.25 no.7
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• pp.35-46
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• 2009

Pressure grouting is a common technique in geotechnical engineering to increase the stiffness and strength of the ground mass and to fill boreholes or void space in a tunnel lining and so on. Recently, the pressure grouting has been applied to a soil-nailing system which is widely used to improve slope stability. The soil-nailing design has been empirically performed in most geotechnical applications because the interaction between pressurized grouting paste and the adjacent ground mass is complicated and difficult to analyze. The purpose of this study is to analyze the increase of pullout resistance induced by pressurized grouting with the aid of performing laboratory model tests and field tests. In this paper, two main causes of pullout resistance increases induced by pressurized grouting were verified: the increase of mean normal stress and the increase of coefficient of pullout friction. From laboratory tests, it was found that dilatancy angle could be estimated by modified cavity expansion theory using the measured wall displacements. The radial displacement increases with dilatancy angle decrease and the dilatancy angle increases with injection pressure increase. The measured pullout resistance obtained from field tests is in good agreement with the estimated one from the modified cavity expansion theory.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.12-18
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• 2024

High-rise, large-scale, and diversification of buildings are possible, and the reduction of concrete cross-sections reduces the weight of the structure, thereby increasing or decreasing the height of the floor, securing a large number of floors at the same height, securing a large effective space, and reducing the amount of materials, rebar, and concrete used for designating the foundation floor. In terms of site construction and quality, a low water binder ratio can reduce the occurrence of dry shrinkage and minimize bleeding on the concrete surface. It has the advantage of securing self-fulfilling properties by improving fluidity by using high-performance sensitizers, making it easier to construct the site, and shortening the mold removal period by expressing early strength of concrete. In particular, with the rapid development of concrete-related construction technology in recent years, the application of ultra-high-strength concrete with a design standard strength of 100 MPa or higher is expanding in high-rise buildings. However, although high-rise buildings with more than 120 stories have recently been ordered or scheduled in Korea, the research results of developing ultra-high-strength concrete with more than 130 MPa class considering field applicability and testing and evaluating the actual applicability in the field are insufficient. In this study, in order to confirm the applicability of ultra-high-strength concrete in the field, a preliminary experiment for the member of a reduced simulation was conducted to find the optimal mixing ratio studied through various indoor basic experiments. After that, 130 MPa-class ultra-high-strength concrete was produced in a ready-mixed concrete factory in a mock member similar to the life size, and the flow characteristics, strength characteristics, and hydration heat of concrete were experimentally studied through on-site pump pressing.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.227-234
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• 2018

Concrete mix design controls the various concrete properties such as workability and strength. Fresh concrete requires workability and the hardened concrete requires compressive strength. If using the concrete from different supplier concurrently, the concrete placed can show different properties unlike originally designed. However most of construction sites place the concrete from several companies. One of the predictable problems is whether the ultimate performance of concrete achieves the originally designed performance after placing the concrete from several companies. Therefore this research aims to keep the concrete quality in the above cases. This research has been done through literature review, questionnaire and the verification at the sample construction site. A literature review describes the general characteristics and quality control of concrete and a questionnaire describes the awareness and implementation of Korean Construction Specification(KCS). The production capacity and the delivery capacity of concrete suppliers is smaller than the daily quantity required on the sample site, therefore the placing of the concrete with different mixing ratio is inevitable and it can not keep the KCS. As a conclusion, this research proposed 5 alternatives and one of them has been adopted, i.e. to unify the concrete mix design of multiple concrete suppliers.

• Korean Journal of Construction Engineering and Management
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• v.21 no.6
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• pp.3-15
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• 2020

For a successful construction project, the requirements of the client should be clearly defined and this should be reflected in the project based on the expertise of each project participant throughout the entire life-cycle. Therefore, it is necessary to establish the concept of Requirements Management to systematize and manage project requirements in terms of information management. This study aims to comprehensively define the concept of requirements management in the architecture industry and to provide a methodological basis for efficiently managing design requirements information by suggesting category of requirements information type and information analysis criteria. In addition, based on the case study, the requirements information was analyzed to propose a systemization methods of requirements management for PMO' design management and information management.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.334-339
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• 2008

Construction that over 70% of the structure consists of concrete gets bigger and higher gradually and the demand of that is increasing as well. However, it's not easy to supply young and skilled persons on construction site because of social avoidance phenomena about 3D occupation, so it causes serious problems like aging and shortage of technicians. To solve the problems, executives related to the construction field make a management effort in various ways such as construction period shortening, labor productivity improvement and good quality but recently, they have an increasing interest in the necessity of the modularization of the high-rise building and the automation of the engineering development for the strengthening of international competitive power as more active and long-term alternatives. Therefore, this study is to propose the roadmap in order to make lots of efforts in developing construction technologies of high-rise buildings by performing a foundation study, the strategy for 4-step research development, on modularized construction system of concrete structure of high-rise buildings through domestic and foreign preceding research analyses associated with optimal design modularization technique, module factory automation and assembly automation of modularized objects.

• Journal of the Korea Institute of Building Construction
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• v.21 no.3
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• pp.231-239
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• 2021

Entering the era of the fourth industrial revolution, information and communication technologies such as CCTV, home network systems and equipment are being used in the construction industry. In particular, in order to increase the autonomy of information and communication technologies in apartments, the government has announced an administrative revision of information and communication-related laws, and companies are focusing on developing technologies such as smart home services. In addition, most domestic and foreign studies on the information and communication work were mainly conducted on technology and management. However there is a lack of research on physical defects affecting the quality of ICT. Therefore, this study collected the defect data registered in the project management system of three domestic construction companies and classified them according to the standards of the Enforcement Decree of the Apartment House Management Act. According to the analysis of the frequency of defects work type, 88.10% of defects occurred in home network equipment work. In addition, analysis of defects type in the four detailed works showed the highest number of operation error. The cause was analyzed and prevention measures and countermeasures were presented in parts of design, construction, and maintenance. The results of this study will improve the quality of apartment housing and be used as basic data for future research on practical defect minimization and prevention measures.