• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.8-13
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• 2017

Nuclear power plant (NPP) constructions are large scale projects that are executed for several years, and schedule control utilizing various schedules is a critically important factor. Recently Korea independently developed the Advanced Power Reactor (APR) 1400 and is building nuclear facilities applying this new reactor type. The construction of Shin-Kori NPP (SKN) Unit 3, which adopted the APR1400, was completed and commercial operation has begun, while, SKN 4, Shin-Hanul NPP (SHN) Units 1&2, and SKN 5&6 are currently under construction. Prior to the development of the APR1400, Korea built 24 reactors and accumulated the schedule data of various reactor types which provided the foundation for schedule reduction to be possible. However, as there is no schedule development and review system established based on the standard schedule data (standard activities, durations, etc.) by reactor type, the process for developing the schedule for new builds is low in efficiency consuming much time and manpower. Also all construction data has been accumulated based on schedule activities. But because the connectivity of activities between projects is low, it is difficult to utilize such accumulated data (causes for schedule delay, causes for design changes, etc.) in new build projects. Due to such reasons, issues continue to arise in the process of developing standard schedule activities and a standard schedule for nuclear power plant construction. In order to develop a standard schedule for NPP construction, i) the development of an NPP standard schedule activity list, ii) development of the connection logic of NPP standard schedule activities, iii) development of NPP standard schedule activity resources and duration, and iv) integration of schedule data need to be performed. In this paper, an analysis was made on the coherence of schedule activity descriptions of existing NPPs by applying the probabilistic methodology on activities with low connectivity due to the utilization of the numbering system of four APR1400 reactors (SHN 1&2 and SKN 3&4).This study also describes the method for developing a standard schedule activity list and connectivity measures by extracting same and/or similar schedule activities.

• 한국안전학회지
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• 제22권5호
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• pp.33-40
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• 2007

Standard safety management costs can not be applied to each site with same rate, it is very difficult, because it depends on the experience, work method, work kind, work progress schedule, and hazard level of each construction company. Therefore, this study is to find out hazard level of each work kinds through questionnaire and interview and investigate analyze the status which standard safety management costs have been used. Also, this study is to show reasonable rates of standard safety management costs in construction industry and to set up countermeasures against those problem after reviewing its status in korea with in Japan and Europe. This study is to investigate eleven project kinds of domestic system, first, and to investigate eleven items of apartment bldg, office. Also this study is to investigate and analyze performed costs of presently processing worker finished work so that it shows a new reasonable rate against standard safety management costs in construction industry, in order to make basical data and material to be systemized.

• Structural Monitoring and Maintenance
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• 제5권1호
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• pp.1-13
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• 2018

The Zhuhai Opera House has an external structure consisting of a type of spatial steel, where the stress of steel elements varies with the ambient temperature. A structural health monitoring system was implemented at Zhuhai Opera House, and the temperatures and stresses of the structures were monitored in real time. The relationship between the stress distribution and temperature variations was analysed by measuring the temperature and stresses of the steel elements. In addition to measurements of the structure stresses and temperatures, further simulation analysis was carried out to provide the detailed relationship between the stress distributions and temperature variations. The limited temperature measurements were used to simulate the structure temperature distribution, and the stress distributions of all steel elements of the structure were analysed by building a finite element model of the Zhuhai Opera House spatial steel structure. This study aims to reveal the stress distributions of steel elements in a real-world project based on temperature variations, and to supply a basic database for the optimal construction time of a spatial steel structure. This will not only provide convenient, rapid and safe early warnings and decision-making for the spatial steel structure construction and operation processes, but also improve the structural safety and construction accuracy of steel space structures.

• International Journal of Railway
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• 제5권3호
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• pp.103-113
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• 2012

Infrastructure costs could be greatly reduced if the need for bridges and tunnels was reduced, or if the line could be shortened. Tilting trains might be a less costly alternative to building new tracks with large curve radii, because tilting trains can negotiate tighter curves without having to decrease their speeds. Tracks built for tilting trains would be cheaper, as they require fewer bridges and tunnels. This paper compares the construction costs of two different options for the new Dodam-Yeoncheong section on the Central line, which includes 148.65 km of new electrified double-track with a design speed of 250 km/h. The first option is to straighten the high-speed line. The second option is to build a line with small radii curves and run tilting trains on the line. In the first option, tunnels would account for about 51% of the new section. In comparison, the second option would have shorter curves and fewer tunnels and bridges which would reduce construction costs. Furthermore, alignment modifications could be made to several segments on the straight line, making the most of the existing roadbed. The analysis concluded that the line suited to tilting trains would be 95.7 million USD cheaper to build the straight route. That is a savings of 2.8% of the total project cost. However, this option would increase the total travel time of the route by 1.2 minutes, which means it is not necessarily the best choice.

• 한국BIM학회 논문집
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• 제5권1호
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• pp.1-7
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• 2015

Modular technology has become a major issue of the construction industries to enhance their productivity. Modular bridge construction generally requires the data exchange between the contractors, designers, fabricators and constructors. Therefore, a readily accessible information model interface module based on BIM technology is essential for their communication during a project life-cycle. In this study, BIM based information model interface module for a modular pier was developed. For the information models, the PBS(Product Breakdown Structure) and LOD(Level of Development) were defined. Next, all components of a modular pier were conducted by the parametric modeling technique, and then 3D cell library interface was developed. An nterface module was also developed using VBA(Visua basic Application) for exchanging a data from 3D model library to other softwares such as Microstation, AutoCad and Excel and was connected with MS Access database. The developed information model interface module would improve the design quality of the modular pier and reduce the time and cost for design. Updated 3D information models could be utilized for the fabrication, assembly, and construction process for modular piers.

• 한국건설관리학회논문집
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• 제8권3호
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• pp.150-158
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• 2007

건축물이 고층화, 대형화되면서 철골구조를 기본골조로 채택하는 경우가 많아지고 있으며, 철골공사의 품질관리는 사전계획단계부터 이루어지며, 단계별 참여자간의 업무 구분 및 연계가 매우 중요하다 이에 본 연구는 철골공사의 품질관리를 보다 원활하게 수행하기 위하여, 기존 철골공사 품질관리업무를 기반으로 업무간 상호관계 및 입출력 정보를 고려한 품질관리 업무 프로세스 모델을 개발하고자 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.609-613
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• 2004

An economic analysis is one of the most dominant factors to determine the project feasibility of super tall building. In economic considerations, it is very important toadopt optimum structural floor systems because these are dependent on both the cost and the duration of construction. The economics affected by structural floor systems are more distinct athigher story. As the story increases, the construction cost of floor system. is accumulated linearly, while the cost of lateral resisting system is increased geometrically. The purpose of this study is to investigate the economical effects of super tall buildings through application of optimum structural floor systems. Three types of structural systems(RC beam-column frame, RC flat plate frame, and Steel frame) of super tall buildings having 50-stories are considered in this study and compared to RC flat plate slab with other systems. Analytical result shows that RC flat plate slab using lightweight concrete ismost effective in both the cost and the duration of construction.

• 한국건설관리학회논문집
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• 제24권5호
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• pp.83-94
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• 2023

In order to devise a rebar usage optimization algorithm, it is necessary to calculate the exact rebar length and revise the arrangement of rebars into special lengths. However, the process of rearranging numerous rebars and manually calculating their quantities is time-consuming and requires significant human resources. To address this challenge, it is necessary to develop an algorithm that can automatically estimate the length of rebars and calculate their quantities. This study aims to create an automatic estimation algorithm that improves work efficiency while ensuring accurate and reliable calculations of rebar quantities. The algorithm considers various factors such as concrete cover, hook length, development length, and lapping length, mandated by the building codes, to calculate the quantity of rebars for wall structures. The effectiveness of the proposed method is validated by comparing the rebar quantities generated by the algorithm with manually calculated quantities, resulting in a difference rate of 1.14% for the hook case and 1.37% for the U-bar case. The implementation of this method enables fast and precise estimation of rebar quantities, adhering to relevant regulatory codes.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.263-270
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• 2017

The precast concrete (PC) structure has been preferred for reasons of shortening the construction time and securing the quality and, in particular, it has a cost saving effect in case of long span and heavy loaded structure with high floor height. Most engineers take it for granted to install the plant produced PC members. Researchers in several papers have argued that slander PC members such as columns and girders can be cost-effective if in-situ production is possible, while ensuring quality equal to or better than in-plant production. However, this argument is not officially accepted because objective verification has not been done. Therefore, the purpose of this study is to experimentally conduct in-situ production of PC members to verify the above claim. For this study, a storage building with long span and heavy loaded structure with high floor height was selected as a case study site. For the site, most of the PC members were supplied from the plant, and some of the columns were produced in the site for this study. As a result, it has been confirmed that it has a cost saving effect of 20% while having superior quality to plant-produced PC columns.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.411-414
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• 2015

The purpose of this study is to conduct a comparative analysis between Korea and the United States of the supply process of unit modular housing at both the factory production phase and the transportation and lifting phase, as part of an attempt to invigorate the unit modular housing market in Korea. Unlike the practice in the United States, one of Korea's unique characteristics is that the floor is constructed with reinforced concrete and hot water heating system. To do this, the wet method in Korea is used that includes concrete placement, curing and constructing hot water floor heating system at the factory production phase, which results in a longer production time and also requires the lifting of heavier loads. In the United States, interior and exterior finishing works of modular housing are performed by different companies, and the distance between the unit module factory and the construction site is quite far. This kind of dualized production structure may cause confusion when it comes to schedule management, procurement management, and stock management. Moreover, problems caused by external environmental factors such as wind and rainfall were reported in the course of long-distance transportation. The results of this case comparison are expected to provide fundamental data that will reduce the amount of trial and error in the unit module production, transportation and lifting work in Korea, which has a comparatively small number of unit modular housing cases.