• Title, Summary, Keyword: 생애주기비용

Search Result 271, Processing Time 0.034 seconds

Optimal Life Cycle Cost Design of a Bridge (교량의 생애주기비용 최적설계)

  • Park, Jang-Ho;Shin, Yung-Seok
    • Journal of the Korean Society of Safety
    • /
    • v.25 no.6
    • /
    • pp.115-122
    • /
    • 2010
  • The importance of the life cycle cost (LCC) analysis for bridges has been recognized over the last decade. However, it is difficult to predict LCC precisely since the costs occurring throughout the service life of the bridge depend on various parameters such as design, construction, maintenance, and environmental conditions. This paper presents a methodology for the optimal life cycle cost design of a bridge. Total LCC for the service life is calculated as the sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The optimization method is applied to design of a bridge structure with minimal cost, in which the objective function is set to LCC and constraints are formulated on the basis of Korean Bridge Design Code. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on damage probabilities to consider the uncertainty of load and resistance. Repair and rehabilitation cost is determined using load carrying capacity curves and user cost includes traffic operation costs and time delay costs. The optimal life cycle cost design of a bridge is performed and the effects of parameters are investigated.

Optimum Service Life Management Based on Probabilistic Life-Cycle Cost-Benefit Analysis (확률론적 생애주기비용-이익분석 기반 수명관리 최적화 기법)

  • Kim, Sunyong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.4
    • /
    • pp.19-25
    • /
    • 2016
  • Engineering structures including civil infrastructures require a life-cycle cost and benefit during their service lives. The service life of a structure can be extended through appropriate inspection and maintenance actions. In general, this service life extension requires more life-cycle cost and cumulative benefit. For this reason, structure managers need to make a rational decision regarding the service life management considering both the cost and benefit simultaneously. In this paper, the probabilistic decision tool to determine the optimal service life based on cost-benefit analysis is presented. This decision tool requires an estimation of the time-dependent effective cost-benefit under uncertainty to formulate the optimization problem. The effective cost-benefit is expressed by the difference between the cumulative benefit and life-cycle cost of a deteriorating structure over time. The objective of the optimization problem is maximizing the effective cost-benefit, and the associated solutions are the optimal service life and maintenance interventions. The decision tool presented in this paper can be applied to any deteriorating engineering structure.

Economics analysis for life cycle cost design of bridges (LCC를 고려한 교량의 경제성 분석)

  • Shin, Yung-Seok;Pack, Jang-Ho;Ahn, Sung-Chan
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.162-165
    • /
    • 2010
  • 합리적인 교량 대안선정을 위해서는 설계 시 경제성, 경관성, 안전성 및 기능성, 유지관리 용이성, 시공성 등 다양한 속성을 고려하여야 한다. 이 중 경제성은 초기비용뿐만 아니라 공용수명에 걸쳐 발생하는 유지관리비용, 보수 보강비용, 해체 폐기비용 등의 합인 총 생애주기비용에 대해 최소의 비용으로 최상의 가치를 창출하도록 하여야 한다. 본 연구에서는 건설계획과정에서 대표적으로 고려될 수 있는 대안으로 세 가지 교량 형식(강상자형교, 소수주형교, PSC-I형 거더교)을 대상구조물로 선정하고 교량의 공용수명은 상태등급곡선으로부터 추정한 내하율 곡선을 사용하여 산정하였다. LCC최적설계를 위해 설계변수, 제약조건, 목적함수를 구성하였고, 총 생애주기비용을 공용수명으로 나눈 연간생애주기비용을 사용하여 하여 합리적인 교량의 경제성 분석을 수행하였다.

  • PDF

Life-Cycle Cost Optimization of Steel Box Girder Bridges (강상자형교의 생애주기비용 최적설계)

  • 조효남;민대홍;권우성
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.15 no.4
    • /
    • pp.557-566
    • /
    • 2002
  • This paper presents an optimum deck and girder system design for minimizing the life-cycle cost(LCC) of steel box girder bridges. The problem of optimum LCC design of steel box girder bridges is formulated as that of minimization of the expected total LCC that consists of initial cost, maintenance cost and expected retrofit costs for strength, deflection and crack. To demonstrate the cost effectiveness of LCC design of steel box girder bridges, the LCC optimum design is compared with conventional design method for steel box girder bridges. From the numerical investigations, it may be positively stated that the optimum design of steel box girder bridges based on LCC will lead to mote rational, economical and safer design.

A Measure for Improving the Systematic Evaluation of the Life Cycle Cost in Technical Proposal Tendering (기술제안입찰에서의 계적인 생애주기비용 평가를 위한 개선방안)

  • Son, Myung-Jin;Hyun, Chang-Taek
    • Korean Journal of Construction Engineering and Management
    • /
    • v.13 no.6
    • /
    • pp.71-83
    • /
    • 2012
  • The use of technical proposal tendering has been expanding recently with the aim of effecting cost reduction, quality enhancement, technological development and value realization centered on multifunctional administrative cities, innovation cities, and the Yongsan relocation project. In line with the increasing interest towards life cycle cost improvement measures as an important evaluation category concerning technical proposal tendering, efforts in preparing measures that can execute the security of credibility and objective evaluation concerning architectural life cycle cost are being made. However, problems such as lack of applicable cases of design development and detail design, distortion of initial construction costs concerning the original plan, combination of constant price and current price, the ambiguity of the calculation standards between tendering corporations, inaccuracy of terms, and insufficient compositional formats concerning life cycle improvement measures are being cited. Accordingly, this study sought to propose a measure to improve the compositional guidelines, format, and standards so that a systematic life cycle cost evaluation can be executed for the reliable distinction of each participating corporation, enhanced credibility and objective evaluation of the life cycle cost improvement measure for technical proposals.

Optimal Life-Cycle Cost Design of Steel Box Girders (강박스 거더의 생애주기비용 최적설계)

  • Shin Yung-Seok;Park Jang-Ho;Lee Hyun-Sub;Ahn Ye-Jun
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.18 no.4
    • /
    • pp.445-452
    • /
    • 2005
  • This paper presents a design method to minimize Life Cycle Cost (LCC) of steel box girders. The LCC considered in this paper includes initial cost, expected life-cycle maintenance cost and repair cost. A load carrying capacity curve is derived from a condition grade curve of steel girders and load tarrying capacity that is measured in safety diagnostic test. And then, optimal design of steel box girders is performed on the basis of load carrying capacity curve. In this paper time and number of times for repair of steel girders are determined based on the calculated load carrying capacity curve. Also, annual costs considering real discount rate are compared and analyzed in various cases. It is concluded that the optimal design of steel box gilders considering LCC by the presented method will lead to more economical and safer girders than conventional design.

Life Cycle Cost Analysis at Design Stage of Cable Stayed Bridges based on the Performance Degradation Models (성능저하모델에 기초한 사장교의 설계단계 생애주기비용 분석)

  • Koo, Bon Sung;Han, Sang Hoon;Cho, Choong Yuen
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.33 no.5
    • /
    • pp.2081-2091
    • /
    • 2013
  • Recently, the demand on the practical application of life-cycle cost effectiveness for design and rehabilitation of civil infrastructure is rapidly growing unprecedently in civil engineering practice. Accordingly, in the 21st century, it is almost obvious that life-cycle cost together with value engineering will become a new paradigm for all engineering decision problems in practice. However, in spite of impressive progress in the researches on the LCC, the most researches have only focused on the Deterministic or Probabilistic LCC analysis approach and general bridge at design stage. Thus, the goal of this study is to develop a practical and realistic methodology for the Life-Cycle Cost LCC-effective optimum decision-making based on reliability analysis of bridges at design stage. The proposed updated methodology is based on the concept of Life Cycle Performance(LCP) which is expressed as the sum of present value of expected direct/indirect maintenance costs with expected optimal maintenance scenario. The updated LCC methodology proposed in this study is applied to the optimum design problem of an actual highway bridge with Cable Stayed Bridges. In conclusion, based on the application of the proposed methods to an actual example bridge, it is demonstrated that a updated methodology for performance-based LCC analysis proposed in this thesis, shown applicably in practice as a efficient, practical, process LCC analysis method at design stage.

A Case Study of Life Cycle Cost Analysis on Pavements in Apartment Complex (단지내 도로포장별 생애주기 비용 분석(LCCA) 사례 연구)

  • Jung, Jong-Suk;Park, Yong-Boo;Sohn, Jeong-Rak
    • LHI Journal of Land, Housing, and Urban Affairs
    • /
    • v.5 no.4
    • /
    • pp.297-303
    • /
    • 2014
  • Recently, block and permeable pavements have been placed in apartment complex. However. it is hard to decide the cycle of maintenance and repair due to lack of performance evaluation criteria for these pavements. This study carried out life cycle cost analysis(LCCA) to present resonable alternatives of the pavements by considering initial construction cost, maintenance and repair cost along with the cycle of repair. According to results of LCCA, the interlocking concrete block pavement is the best alternative when the repair cycle of 20years is assumed, while asphalt concrete pavement is the best alterative when the repair cycle of 10years is assumed. Therefore, the repair cycle is most important factor to select alternative. Also, it is necessary to develop resonable performance evaluation index to quantify the cycle of maintenance and repair in the future.

Development of Bridge Maintenance Method based on Life-Cycle Performance and Cost (생애주기 성능 및 비용에 기초한 교량 유지관리기법 개발)

  • Park, Kyung Hoon;Kong, Jung Sik;Hwang, Yoon Koog;Cho, Hyo Nam
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.26 no.6A
    • /
    • pp.1023-1032
    • /
    • 2006
  • In this paper, a new method for the bridge maintenance is proposed to overcome the limit of the existing methods and to implement the preventive bridge maintenance system. The proposed method can establish the lifetime optimum maintenance strategy of the deteriorating bridges considering the life-cycle performance as well as the life-cycle cost. The lifetime performance of the deteriorating bridges is evaluated by the safety index based on the structural reliability and the condition index detailing the condition state. The life-cycle cost is estimated by considering not only the direct maintenance cost but also the user and failure cost. The genetic algorithm is applied to generate a set of maintenance scenarios which is the multi-objective combinatorial optimization problem related to the life-cycle cost and performance. The study examined the proposed method by establishing a maintenance strategy for the existing bridge and its advantages. The result shows that the proposed method can be effectively applied to deciding the bridge maintenance strategy.

  • PDF

Life-Cycle Cost-Effective Optimum Design of Steel Bridges Considering Environmental Stressors (환경영향인자를 고려한 강교의 생애주기비용 최적설계)

  • Lee, Kwang Min;Cho, Hyo Nam;Cha, Cheol Jun
    • Journal of Korean Society of Steel Construction
    • /
    • v.17 no.2
    • /
    • pp.227-241
    • /
    • 2005
  • This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology for steel bridges considering the long-term effect of environmental stressors such as corrosion and heavy truck traffics on bridge reliability. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost, and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure, which depends upon the prior and updated load and resistance histories, should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model, which takes into consideration corrosion initiation, corrosion rate, and repainting effect, are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40m+50m+40m=130m). Various sensitivity analyses are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the volume of truck traffic significantly influence the LCC-effective optimum design of steel bridges. Thus, these conditions should be considered as crucial parameters for the optimum LCC-effective design.