• Smart Structures and Systems
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• 제4권5호
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• pp.641-653
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• 2008

This paper proposes a practical and realistic method to establish an optimal lifetime maintenance strategy for deteriorating bridges by considering the life-cycle performance as well as the life-cycle cost. The proposed method offers a set of optimal tradeoff maintenance scenarios among other conflicting objectives, such as minimizing cost and maximizing performance. A genetic algorithm is used to generate a set of maintenance scenarios that is a multi-objective combinatorial optimization problem related to the lifetime performance and the life-cycle cost as separate objective functions. A computer program, which generates optimal maintenance scenarios, was developed based on the proposed method using the life-cycle costs and the performance of bridges. The subordinate relation between bridge members has been considered to decide optimal maintenance sequence and a corresponding algorithm has been implemented into the program. The developed program has been used to present a procedure for finding an optimal maintenance scenario for steel-girder bridges on the Korean National Road. Through this bridge maintenance scenario analysis, it is expected that the developed method and program can be effectively used to allow bridge managers an optimal maintenance strategy satisfying various constraints and requirements.

• Structural Engineering and Mechanics
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• 제31권1호
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• pp.11-24
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• 2009

In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.

• Advances in environmental research
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• 제3권4호
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• pp.367-377
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• 2014

In this study, we investigated a life cycle assessment (LCA) of six roof-waterproofing systems [asphalt (C1), synthetic polymer-based sheet (C2), improved asphalt (C3), liquid applied membrane (C4), Metal sheet with asphalt sheet (N1), and liquid applied membrane with asphalt sheet (N2)]for reinforced concrete building using an architectural model. To acquire accurate and realistic LCA results, minimum units of material compositions for life cycle inventory and real data for compositions of waterproofing materials were used. Considering only materials and energy demands for waterproofing systems per square meter, higher greenhouse gas (GHG) emissions could be generated in the order of C1 > N2 > C4 > N1 > C2 > C3 during construction phase. However, the order was changed to C1 > C4 > C3 > N2 > N1 > C2, when the actual architecture model was applied to the roof based on each specifications. When an entire life cycle including construction, maintenance, and deconstruction were considered, the amount of GHG emission was in the order of C4 > C1 > C3 > N2 > C2 > N1. Consequently, N1 was the most environmental-friendly waterproofing system producing the lowest GHG emission. GHG emissions from maintenance phase accounted for 71.4%~78.3% among whole life cycle.

• 한국건설관리학회논문집
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• 제13권2호
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• pp.11-24
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• 2012

최근 공공사업 발주조건에 BIM(Building Information Modeling)이 의무화되고 있고, 실무 도입을 통한 성공 사례가 증가되면서 건설 분야의 BIM 도입이 본격화되고 있다. 그러나 기존의 BIM 관련 연구는 대부분 설계 또는 시공단계에 한정되어 수행됨에 따라 건설프로젝트의 생애주기를 고려하지 못하고 있고, 특정 업무지원 기능 위주로 진행되고 있다. 따라서 본 연구에서는 건설공사 프로젝트의 기획부터 유지관리단계의 생애주기 동안 단계별 BIM 적용이 가능한 통합 BIM 운영 프로세스를 제안하고 이를 토대로 통합 BIM 시스템을 개발한다. 이를 위해 교량공사를 대상으로 수행단계별 정보체계를 분석하여 BIM 활용 기능과 적용 프로세스를 제시하였으며, 이에 근거하여 수행단계별 BIM 운영 시스템을 구축하였다. 연구에서는 개발된 시스템의 실무 적합성 검증을 위해서 사례적용과 건설 실무자의 활용성 설문 조사를 수행하였다. 이러한 BIM 통합 운영체계는 생애주기를 고려한 건설공사의 3차원 기반 통합정보관리체계로 활용성이 기대된다.

• 한국전자거래학회지
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• 제9권2호
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• pp.87-108
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• 2004

기존의 건설산업에서는 건설산업의 전 생명주기 동안 발생하는 모든 설계도면과 시방서 및 문서를 방대한 분량의 종이로 관리하여 왔다. 그 결과 유사 공사 실적자료의 재사용, 설계자와 시공자간의 정보교환ㆍ공유에 있어 공사의 실적저하, 예산낭비 등의 문제를 가져왔다. 이러한 문제를 해결하기 위하여 건축 정보의 교환ㆍ공유에 기존의 형식인 종이대신 전자화 된 도면과 문서를 사용하도록 하는 업무개선의 요구가 있어왔고, 이러한 문제를 총체적으로 해결하기 위하여 정부차원의 건설분야 전자거래프로그램이 요구되게 되었다. 본 논문은 건설CALS/EC(Continuous Acquisition and Life Cycle Support/Electronic Commerce)와 관련된 요소기술의 국내외적인 적용사례를 바탕으로 하여 도면전자납품을 위한 건설 CALS/EC에서 표준기술이 되는 요소기술의 활용방안과 향후 개발 방향에 관하여 제시해 보고자 한다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.170-175
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• 2008

가상건설시스템 개발연구단은 국토해양부와 한국건설교통기술평가원의 지원 하에 설립되었다. 본 연구단은 건설프로젝트의 생산성 향상, 고 부가가치 사업 창출, 해외건설시장에서의 경쟁력 확보라는 목표를 가지고 연구를 수행 중에 있다. 가상건설 시스템은 건축물의 전 생애주기에서 발생되는 정보를 효과적으로 공유할 수 있도록 3D 및 정보 기반의 설계, 엔지니어링, 건설관리 업무를 지원하게 된다. 위의 목표를 달성하기 위해서 연구단은 가상건설시스템 하위에 다양한 기능을 수행하는 모듈들을 개발하는 데에 연구의 초점을 맞추고 있다. 첫째, 3D 기반 구조 설계 설비 및 견적시스템 개발이다. 둘째, 가상현실 기법을 활용한 기획단계에서의 프로세스 시뮬레이션 및 사업성 분석 시스템 개발이다. 셋째, 건설프로젝트에서 다루어지는 모든 정보를 관리할 수 있는 CPLM(Construction Project Life-cycle Management)을 개발하는 것이다. CPLM은 3D 기술과 정보 기반 협업을 통한 의사결정 지원 시스템이다. 이와 같은 본 연구단의 최종목표에 도달하기 위하여 2차 년도에 가상건설 프로토타입 시스템을 개발 완료하였고, 3차 년도 가상건설 시스템의 각 모듈 완성 및 시스템 통합을 목표로 연구를 진행하고 있다. 본 연구는 향후 건설산업에서 필수개념으로 자리잡게 될 BIM의 국가적 차원의 연구라는 점에서 시사하는 바가 크다고 할 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.574-580
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• 2005

Recently, the number of bridges and tunnels in railway is increasing due to the super high-speedy of train. Also, because of successively accidents of civil structures such as bridges and dams, the importance of maintenance become influential. The purpose of this study is to show the probabilistic life cycle cost analysis technique(PLCC) of the railroad bridge as pubic-infrastructures, and reasonably to indicate the economy in life cycle cost(LCC) through a case study. Rationally for life cycle cost analysis, the data gathered through many materials considered the uncertainty such as covariance. As a result, it is indicated that prestressed concrete bridge is pretty more cost-effective during life-cycle than preflex as well as steel box bridge. In future, if the construction of database and maintenance materials for railroad infrastructure is actualized, the life cycle cost analysis for railroad can be conducted easily and practically.

• 한국BIM학회 논문집
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• 제5권2호
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• pp.34-45
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• 2015

As buildings become larger and more complicated, construction costs have increased with a considerable effect on buildings' Life Cycle Cost (LCC). However, there has been little consideration on economic aspects in the selection of construction materials due to limited information on the materials and dependency in architects' experience and inefficiency in cost estimation, causing design changes, increase in maintenance cost, difficulty in budgeting, and decrease in building performance. To solve these problems, this study proposed a BIM-based material selection model which reflects the comprehensive economic efficiency of building materials. Our cost prediction model can estimates the material-related cost during the entire building life cycle. Furthermore, we implemented the proposed model in connection with BIM, which can analyze and compare LCC by material. Through the validation of the model, we could confirm the necessity of LCC-based material selection in comparison with the conventional cost-centered material selection.

• Architectural research
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• 제15권3호
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• pp.143-150
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• 2013

The Korean government recently has rediscovered the potential value of Han-Ok, the Korean traditional house, as an eco-friendly building. In order to objectively verify the environmental performance of Han-Ok as a low carbon green building, this paper suggests the analysis method of GHG emission load of Korean traditional house, based on Life Cycle Assessment, which is commonly abbreviated to "LCA". The environmental impacts caused by building construction and operation can be analyzed through the sum of input and output data from every phase. The study particularly describes the GHG reduction effect by using traditional building materials such as wood products, traditional clay roof tiles, and mud, which are mainly used to construct Han-Ok. Also the study proposes the method for comparative analysis of quantity of GHG emissions in building's entire life cycle so that the data can be used as a reliable basis to optimize the environmental performance of building.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2004년도 춘계 학술발표회 논문집
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• pp.353-358
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• 2004

In recent, the trends in national energy Policy are established in the context of the integrated risk estimation for various national electricity generating options. The approach takes account of health, environmental, economic, and social aspects of electricity generation systems. In the present work, nuclear, coal, and LNG sources are chosen because these hold more than 90% of national total electricity generation in a descending order. A life cycle assessment (LCA) methodology is used for comparing environmental impacts of these options during the life cycle such as construction, operation as well as disposal stages. Here, the LCA consists of life cycle inventory analysis, classification/selection process of impact categories, characterization process, and normalization process of each category. LCA can be an useful tool for environmental impact assessment of future national energy options. At the planning stage of future energy Policies, the results of LCA would be taken into consideration. According to data update at the construction and disposal stages, the LCA needs to be conducted iteratively.