• Structural Engineering and Mechanics
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• 제59권4호
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• pp.621-652
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• 2016

A new cable-supported bridge model consisting of suspension parts, self-anchored cable-stayed parts and earth-anchored cable-stayed parts is presented. The new bridge model can be used for suspension bridges, cable-stayed bridges, cable-stayed suspension bridges, and partially earth-anchored cable-stayed bridges by varying parameters. Based on the assumption that each structural member is in either an axial compressive or tensile state, and the stress in each member is equal to the allowable stress of the material, the material quantity for each component is calculated. By introducing the unit cost of each type of material, the estimation formula for the cost of the new bridge model is developed. Numerical examples show that the results from the estimation formula agree well with that from the real projects. The span limit of cable supported bridge depends on the span-to-height ratio and the density-to-strength ratio of cables. Finally, a parametric study is illustrated aiming at the relations between three key geometrical parameters and the cost of the bridge model. The optimization of the new bridge model indicates that the self-anchored cable-stayed part is always the dominant part with the consideration of either the lowest total cost or the lowest unit cost. It is advisable to combine all three mentioned structural parts in super long span cable supported bridges to achieve the most excellent economic performance.

• 한국전산구조공학회논문집
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• 제22권1호
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• pp.53-63
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• 2009

초고층건물의 구조설계에 고강도강재를 활용하는 것은 수직 부재 크기의 감소로 인한 건축 계획적 측면의 용이성 그리고 골조 물량의 감소로 인한 구조 및 시공 측면에서의 비용적 효율성 등이 예상되지만 적용사례 부족 및 합리적 설계 방법의 부재 등의 이유로 인해 고강도강재는 일부 건축물에서 제한적으로 사용피고 있다. 특히, 많은 부재로 구성되는 초고층 건물에서 강재의 적절한 강도를 고려한 경제적 단면 성능의 결정은 결코 쉬운 일이 아니다. 이러한 이유로 인해 최근 많은 초고층건물들은 콘크리트를 이용하여 계획되거나 시공되고 있다. 그러므로 본 논문에서는 초고층건물 구조설계에서 강재의 적절한 강도와 사용위치를 합리적으로 결정하여 구조비용을 최소화할 수 있는 초고층건물 구조비용 최적화기법을 개발하였다. 개발된 최적설계기법을 건물골조시스템의 35층 건물의 구조 설계에 적용하여 효율성과 적용성을 평가하였다. 적용 결과, 제안된 최적설계기법은 설정된 제약조건을 만족시키며 최적의 구조비용을 안정적으로 산출할 수 있음을 확인할 수 있었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.719-726
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• 2005

The optimal design was performed for the bridge superstructure composed of steel box girders and concrete deck considering life cycle cost. The service life of the superstructure was estimated, after load carry capacity curves for steel girder and concrete deck were derived on the basis of condition grade curves and maintenance histories. The object function was determined as life cycle cost, including initial cost, total maintenance cost, disposal cost and user cost, for a period of the estimated service life. The optimal design of the superstructure was performed for the various service lifes. The annual costs were used to compare calculated results and to get the most economical design. Also this paper presents reasonable idea for the use of user cost with uncertainty.

• 대한조선학회논문집
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• 제45권2호
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• pp.151-156
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• 2008

It is necessary to perform the research works on the general structural designs and optimum structural designs of double hull tankers and bulk carriers due to the newly built Common Structural Rules(CSR). In this study, an optimum structural design of a mid-ship part of double hull oil tanker was carried out by using the CSR. An optimum structural design program was developed by using the Pareto optimal based multi-objective function method. The hull weight and fabrication cost obtained by the single and multi-objective function methods were compared with existing ship by the consideration of CSR and material cost which is recently increasing.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.387-390
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• 2008

The importance of the life cycle cost analysis for construction projects of bridge has been recognized over the last decades. Accordingly, theoretical models, guidelines, and supporting softwares have been developed for the life cycle cost analysis of bridges. However, it is difficult to predict life cycle cost considering uncertainties precisely. This paper presents methodology for optimal design of substructure for a steel box bridge. Total life cycle cost for the service life is calculated as sum of initial cost, damage cost considering uncertainty, maintenance cost, repair and rehabilitation cost. The optimization method is applied to design of a bridge substructure with minimal cost, in which the objective function is set to life cycle cost and constraints are formulated on the basis of Korean Bridge Design Specification. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on the damage probabilities to consider the uncertainty of load and resistance. An advanced first-order second moment method is used as a practical tool for reliability analysis using damage probability. Maintenance cost and cycle is determined by a stochastic method and user cost includes traffic operation costs and time delay costs.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.237-238
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• 2012

As a way to improve productivity and integrated project delivery in construction industry, BIM(building Information Modeling) using IT technique is being studied and applied recently. S-BIM application Process was established that enable efficient work through Structural BIM detailed Model in consideration of the collaboration among relevant fields. This study has the objective applying S-BIM technique to enable effective Cost Analysis in initial design phase and presenting the method for practical works using Construction Cost Analysis Process based on S-BIM.

• 한국해양공학회지
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• 제23권3호
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• pp.1-5
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• 2009

It is necessary to develop an efficient optimization technique to optimize engineering structures that have given design spaces, discrete design values, and several design goals. In this study, an optimum algorithm based on the genetic algorithm was applied to the multi-object problem to obtain an optimum solution that simultaneously minimizes the structural weight and construction cost of panel blocks in ship structures. The cost model was used in this study, which includes the cost of adjusting the weld-induced deformation and applying the deformation control methods, in addition to the cost of the material and the welding cost usually included in the normal cost model. By using the proposed cost model, more realistic optimum design results can be expected.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.549-556
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• 2006

Life cycle cost is one of important factors in the evaluation of economy feasibility. Load carrying capacity curves for girders and decks are derived on the basis of bridge diagnostic results and condition grade curves to determine the service life and life cycle profile. The total life cycle costs including initial cost, damage cost, maintenance cost, user cost, and etc for the service life are calculated for steel box girder, PSC-I girder and rationalized plate girder. The optimal designs are performed for various service lifes and different superstructure types. The effects of parameters on the life cycle cost are investigated and the economy feasibility is evaluated through the sensitivity analysis.

• Advanced Composite Materials
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• 제16권2호
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• pp.135-149
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• 2007

In the automobile industry, structural health monitoring of fiber reinforced polymer composite parts is a widespread need for maintenance before breakdown of the functional elements or a complete vehicle. High performance sensors are generally used in many of the structural health monitoring operations. Within this study, a carbon fiber sewing thread has been used as a low cost laminate failure sensing element. The experimentation plan was set up according to the electrical conductance and flexibility of carbon fiber threads, advantages of preforming operations, and sewing mechanisms. The influence of the single thread damages by changing the electrical resistance and monitoring the impact location by using carbon thread sensors has been performed. Innovative utilization of relatively cost-effective carbon threads for monitoring the delamination of metallic inserts from the basic composite laminate structure is a highlighting feature of this study.

• 한국공간구조학회논문집
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• 제17권1호
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• pp.85-92
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• 2017

The objective of this paper is to suggest structural design for the long-life housing apartment complex to save the construction cost. The key is to use unavailable underground space due to bearing walls or bad configuration of columns in apartments as the parking space. Therefore, the structural plan of apartment buildings considering the parking section in the underground should be designed. After analytical resutls of three cases, it is significant effect in saving construction cost.