• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.198-199
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• 2022

Reinforced concrete is the most widely used construction method for constructing structures. There is a lot of process for constructing Reinforced concrete structures such as installing rebars, molds and support, mixing and placing concrete, and curing. So the reinforced concrete work accounts for a large part of the total construction cost for constructing structure. For this reason a reasonable standard for estimating the cost of reinforced concrete construction has to be established and it will be possible to secure appropriate costs for construction work. In this study, we analyze the revision factors of the standard for estimating the cost of reinforced concrete construction and present them to secure reasonable construction costs.

• Korean Journal of Construction Engineering and Management
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• v.6 no.5 s.27
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• pp.119-127
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• 2005

According to the recent systemic changes such as construction market reduction, five days per week system, introduction of construction duration reduction bidding system and post-construction sale system, the bidding competition have been enhanced. However, there are many construction schedule risks which could delay construction completion. Without the proper identification of construction schedule risks and the structured construction schedule risk management, the competitive advantages of construction project could not be made. Previous researches to solve the problem have been focused on the construction schedule categorization, construction schedule management, and the system development to manage the construction schedule risk. Therefore, this study selected the reinforeced concrete construction as the studied work due to the major impact characteristics on the total construction duration and the quite accident rate, and then proposed the real construction schedule risks of reinforced concrete construction and the construction risk management method based on the previous studies, many times of expert interviews and brainstorming.

• The Journal of Engineering Geology
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• v.13 no.4
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• pp.491-496
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• 2003

본 기술은 암반사면 보강공법에서 철근보강재인 네일(Nail)에 원추형콘(철근 규격에 따라 기울기 $19~23^{\circ}$, 높이 40~45mm, 아랫변 65~70mm)을 일정한 간격으로 다수 장착하여 그라우트재와 원 지반까지 방사입체형으로 힘을 미치게 하는 암반사면 보강공법이다. 본 신기술 공법은 네일링 공사 시 원추형 콘을 장착, 삽입함으로서 부착력과 인발력을 증가시켜 비탈면 보강공사 시에 안전성을 높인 공법이다. 따라서 네일링공법을 사면붕괴 방지공사에 적극 활용할 수 있으므로 네일링 공법의 사용을 활성화 하며, 지진이나 지반변형 등 외력에 의한 사면붕괴를 사전에 방지할 수 있어 사면재해를 미연에 방지하는 효과가 있다. 또한 현재가지 네일링공법은 인발톤수가 적고 네일에 대한 신빙성 결여로 아주 적은 인발톤수를 필요로 하는 현장이외에는 사용을 기피하는 일이 많았다. 그러나 본 원추형 콘네일 공법은 어스앙카, 록앵커, 보강토공법, 지지말뚝공법, 옹벽 등에 대한 대체공법으로 이용할 수 있는 여건이 충족됨으로 사면보강재로서의 사용 확산이 기대된다.

• Journal of the Korea Institute of Building Construction
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• v.5 no.4 s.18
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• pp.99-106
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• 2005

With labor shortage and high-wage, the construction cost is rising and the construction-business is dull, demanding the construction environment of Korea to raise profitability through major cost savings and rationalization of construction management. Therefore, in this study, to improve many problems found in calculating rebar quantity for capital expenditure programming which is considered the beginning stage of rebar work. and to improve problems such as no grasping of rebar loss due to lack of systematic management in order/purchase stage and construction management stage, a rebar information-management-system was found and preyed. The relation database was designed for the rebar information management system by analyzing work process of a rebar manufacturing plant, as the rebar information that is necessary in a rebar manufacturing plant if similar to that of a purchasing department of general construction company. The Proposed rebar information management system was implemented in two large rebar production plants. The implementation of the proposed system showed that the system increased work efficiency, reduced the management manpower, and improved the project-integrated management

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.132-135
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• 2011

최근 설계 단계에서 설계품질 향상과 시공 단계에서 비용 절감을 효과를 기대하며 3차원 BIM 관련 기술에 대한 관심이 높아가고 있으며, 또한 부분적으로 기술 도입 효과가 나타나고 있다. BIM 기술은 크게 BIM 도구를 활용하여 설계정보를 디지털화하는 모델링 단계 기술과 BIM 모델로부터 설계 정보를 추출하여 업무 진행에 필요한 형태로 가공, 변환하는 정보 활용 기술로 구분하여 생각할 수 있다. BIM 기술에 대한 근자의 높은 관심에도 불구하고 실제 현장에 적용되어 가시적인 성과를 내는 데에 한계를 보이고 있는 이유 중 하나로 후자의 정보 추출 및 활용 기술의 범위와 완성도의 한계를 들 수 있다. 즉 많은 노력을 통하여 BIM 모델을 구축하더라도 이를 기반으로 물량산출, 도면 생성 등 가장 기본적인 업무조차도 현장에서 바로 사용할 수 있는 수준의 기능이 제공되고 있지 않다. 본 연구에서는 건축 골조를 대상으로 3차원 골조 모델을 이용하여 골조 물량, 특히 정확한 물량산출이 상대적으로 어려운 철근에 대하여 철근의 이음, 정착 등이 고려된 실행물량을 산출할 수 있는 시스템을 설계하고 구현하였다. 또한 3차원 모델을 기반으로 철근 배근시공도와 가공일람표를 관련 기준에 따라 정확히 자동 작성함으로써 골조공사가 효율적으로 수행되고, 특히 정확한 이음 및 정착과 가공 계획을 통하여 철근 손실율을 최소화함이 기대된다. 본 논문에서는 이러한 BIM 기반 골조 물량산출 및 도면생성 시스템과 관련하여 주요 시스템 설계 내용과 구현 결과에 대하여 기술한다.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.430-439
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• 2002

The development of reinforcing steel is required in reinforced concrete structures. The standard hooks that have been widely used for the tensile development in the beam-column joints tend to create difficulties of construction such as steel congestion as the member cross sections are becoming smaller due to the use of higher strength concrete and higher grade steel. Using the reinforcing bars with end mechanical anchoring device (headed reinforcement) provides potential economies in construction such as reduction in development lengths, simplified details, and improved responses to cyclic loadings. In this paper, the pullout strengths and behaviors of the headed reinforcement were experimentally studied. In 33 pullout tests performed using D25 deformed reinforcing bars, the test parameters were embedment depth, edge distance, head size, and the use of transverse reinforcement. The pullout strengths determined from tests closely agreed with the pullout strengths predicted using the CCD method. The pullout strengths increased with increasing embedment depths nd edge distances. The strengths tend to increase with the use of larger heads. From the experimental program where the effect of the transverse reinforcement was examined, a modification factor to the CCD was suggested to represent the effect of such reinforcement that is installed across the concrete failure plane on the pullout strengths.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.6
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• pp.567-576
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• 2017

The object of this research is an establishment of BIM-based quantity takeoff(QTO) and cost estimation guidelines for reinforcement concrete structures focused on improvement of field applicability in transition period from 2D drawing-based environment to 3D BIM-based environment. Preliminary studies on existing guidelines and standards for BIM modeling, QTO and cost estimation of reinforcement concrete structures are performed, and then a standardization of BIM-based cost estimation process is proposed through comparative analysis between 2D drawing-based cost estimation process and 3D BIM-based. In addition, modeling, QTO, and cost estimation processes of cost-BIM model for RC structures are conducted. The contributions of this research and the guidelines suggested by this research are 1) lowering barriers to entity to the new BIM-based environment for small size companies, 2) reducing construction cost by a close estimate, 3) establishing the foundation for integrated management of informations through construction project life cycle, 4) and ultimately, developing the BIM ecosystems.

• Tunnel and Underground Space
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• v.9 no.1
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• pp.20-26
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• 1999

The completion of the Bakun Diversion Tunnel is subsequently to the Main Dam construction. Therefore, the completion date is very important for the Bakun Hydroelectric Project. Generally, the tunnel lining work as a finishing phase of the tunnelling project occupies a important portion as well as an excavation and a support work of the tunnels in respect to the construction cost and period. Internal section of Bakun Diversion Tunnel is designed circular shape to reduce the roughness of the water flow with 12 meters in diameter of total length 4314.6 meters of 3 tunnels. The lining thickness is varied between 500 mm and 700 mm depending on the structural condition. From the original Tender design of the Bakun tunnels, the required quantity of steel bars was 5,985 ton designed by Reinforced Concrete (RC) through the entire tunnel linings. During the detail design stage by the consideration of the rock conditions and various load conditions, we could suggest five kinds of RC lining type including plain concrete lining type. Through the detail design modification, we could reduce the required amount of steel bars to 2,178 ton, as a half of original Bill of Quantity. Finally, this design modification give us the time and cost saving effect to catch up the construction progress in time.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.125-132
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• 2010

Recently, construction companies have had difficulty in managing their business due to economic hardship domestically and abroad, decreased orders, and low profitability due to intensified competition. To address these issues, construction companies need to develop or introduce construction methods that improve productivity. The purpose of this study is to investigate a re-bar construction method that reduces the high expenses of transport by folding a pre-fabricated re-bar cage. It was concluded that the application of rebar pre-fabrication would be activated and the productivity of construction sites improved by adopting the folding rebar pre-fabrication method.

• Korean Architects
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• no.5 s.99
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• pp.61-70
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• 1977