• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.181-193
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• 2004

A life cycle cost analysis model for public water supply systems should be different from the ones for other civil and architectural facilities as the operation and the maintenance cost of the water supply systems mainly come from the various mechanical systems and the pipeline systems of the collecting/treating/distributing facilities. This paper presents a cost classification scheme and a probabilistic life cycle cost analysis (PLCCA) model for public water supply systems. A value analysis (VA) procedure that is well suited for practical purposes is also presented. The presented probabilistic life cycle model and the value analysis procedure were applied to a real world project, and this case study is discussed in the paper. The model and the procedure presented in this study can greatly contribute to the value-oriented design alternative selection, the estimation of the maintenance cost, and the allocation of budget for water supply system construction projects.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.573-578
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• 2009

Previous research on super high rise buildings focused mostly on the use of public space from building plan perspective, survey of residents' satisfaction evaluation, construction technology and structural technology. But little research is done on the economic analysis of landmark factors. The purpose of this study is to find landmark factors that can be quantitatively measured, collect data on super high rise residential buildings in Seoul. Find the intrinsic values of the landmarks, and analyze how these values differ in areas with different densities, i.e. in 3 Gangnam-gus & Yeongdeungpo-gu and in other areas. It is expected that the results of this study can be used to set an appropriate price of super high rise building in consideration of its landmark value in different area

• Computers and Concrete
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• v.16 no.1
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• pp.49-65
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• 2015

It is hard to guarantee the strict synchronization of all the jacking-up points in the integral jacking of a large-span continuous box girder bridge. This paper took the Hengliaojing Bridge as background, which need jacking up as an object with 295m length and more than 10,000tons weight, adopted 3D software to calculate the unsynchronized jacking-up working conditions, and studied the relationships between the unsynchronized vertical difference and the girder's deformation behaviour. The aim is to verify the maximum value of the unsynchronized vertical difference, and guide the construction and ensure safety. The monitoring system with its contents is introduced corresponding to the analysis. The results of the deck relative elevations prove that it is difficult to avoid the deck torsional deformation for jacking different; especially the side span shows more deformations for its smaller stiffness. The maximum difference is smaller than the limited value with acceptable stresses in the sections. The jacking heights of the pier in each construction step are controlled regularly according to the design. The shifting of the whole bridge in longitudinal direction is smaller than in transverse direction. The several beginning steps are the key to adjust their support reactions. This study is one parts of the fundamental research for the code "Technical specification for bridge jacking-up and reposition of China". The whole synchronous jacking project of the main bridge set a world record by the World Record Association for the whole bridge jacking project with the longest span of the world.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.141-144
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• 2013

This paper presents a system called a Cash-flow based Construction Schedule Optimization system(CfSO). The existing CPM effectively handles schedule and cost management. However, funding strategy should be considered to obtain maximum profit and to progress a project favorably. One of measures is to coordinate the contract terms between owner and subcontractors (or suppliers). Contractor may decrease the interest cost attributed to project financing by adjusting the timing of cash-inflows and cash-outflows. It is an excellent method maximizing profits. This paper presents a method to estimate the amount of a cash-flow occurred periodically by integrating the terms of contract into scheduling. The proposed method is implemented as a system prototype in Microsoft Excel. This system provides a user an automated tool that identifies an optimal schedule that secures maximum profit by adjusting start and finish times of non-critical activities' free-floats without affecting on the project completion time. This system supports a project manager to establish an optimum project schedule and identifies profitable contractual conditions against to a construction owner.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.196-203
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• 2013

Environmental problems like global warming have now become important issues that should be considered in all industries, including construction. In South Korea, many studies have been conducted to achieve the government's goals of reduction in environmental impacts. However, the research on buildings has only focused on CO₂ emission as a research target despite the fact that other environmental impacts resulting from ozone depletion and acidification should also be considered, in addition to global warming. In this regard, this study attempted to propose assessment criteria and methods to evaluate the environmental performance of the structures from various aspects. The environmental impact category can be divided into global impacts, regional impacts, and local impacts. First, global impacts include global warming, ozone layer depletion, and abiotic resource depletion, while regional impacts include acidification, eutrophication, and photochemical oxidation. In addition, noise and vibration occurring in the building construction phase are defined as local impacts. The evaluation methods on the eight environmental impacts will be proposed after analyzing existing studies, and the methods representing each environmental load as monetary value will be presented. The methods presented in this study will present benefits that can be obtained through green buildings with a clear quantitative assessment on structures. Ultimately, it is expected that if the effects of green buildings are clearly presented through the findings of this study, the greening of structures will be actively expanded.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.163-164
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• 2023

The active promotion of construction technology application, aimed at cost reduction, construction time shortening, and performance enhancement during the implementation of Value Engineering (VE) in design, is underway. However, in the process of deriving VE ideas, it is common to simply reuse VE ideas from similar past construction projects, and the application of construction technology is often insufficient. Therefore, in this study, we intend to establish a database linking construction technology information with Building Information Modeling (BIM) models to activate the application of construction technology in the process of deriving VE ideas.

• Steel and Composite Structures
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• v.21 no.1
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• pp.177-194
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• 2016

The cable-supported ribbed beam composite slab structure (CBS) is a new type of pre-stressed hybrid structure. The standard construction method of CBS including five steps and two key phases are proposed in this paper. The theoretical analysis and experimental research on a 1:5 scaled model were carried out. First, the tensioning construction method based on deformation control was applied to pre-stress the cables. The research results indicate that the actual tensile force applied to the cable is slightly larger than the theoretical value, and the error is about 6.8%. Subsequently, three support dismantling schemes are discussed. Scheme one indicates that each span of CBS has certain level of mechanical independence such that the construction of a span is not significantly affected by the adjacent spans. It is shown that dismantling from the middle to the ends is an optimal support dismantling method. The experimental research also indicates that by using this method, the CBS behaves identically with the numerical analysis results during the construction and service.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1039-1046
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• 2018

This paper presents a limit analysis of the series of construction stages of shallow tunneling method by investigating their respective safety factors and failure mechanisms. A case study for one particular cross-section of Beijing Subway Line 7 is undertaken, with a focus on the effects of multiple soil layers and construction sequencing of dual tunnels. Results show that using the step-excavation technique can render a higher safety factor for the excavation of a tunnel compared to the entire cross-section being excavated all at once. The failure mechanisms for each different construction stage are discussed and corresponding key locations are suggested to monitor the safety during tunneling. Simultaneous excavation of dual tunnels in the same cross-section should be expressly avoided considering their potential negative interactions. The normal and shear forces as well as bending moment of the primary lining and locking anchor pipe are found to reach their maximum value at Stage 6, before closure of the primary lining. Designing these struts should consider the effects of different construction stages of shallow tunneling method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.170-175
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• 2007

Recently, construction industry in Korea is considering of various approaches for improving productivity and thus enhancing the competitive capacity in the global market. To this end, Korean Ministry of Construction & Transportation has launched R&D project in the field of automation, information systems, high value-added techniques. Furthermore, a new era of cities such as U-city and Eco-city is coming due to the government strategy for developing the country. In the regards of methodological development and trends of construction projects stated above, conventional methods for managing the projects is not likely to guarantee the success. Especially, in the planning and maintenance phases of such large scale cities, a new paradigm should be introduced. We thought of it as 3D object based simulation system for city planning. This paper describes the concept of the system.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.459-468
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• 2005

International contractors must consider the substantial risks related to unexpected foreign exchange fluctuation incurred by conducting their business and using foreign currencies in foreign countries. Most international contractors attempt to minimize foreign exchange exposure within a manageable range because it may influence the company's fundamental financial structure, reduce market value or profit margins, or disrupt ongoing and future projects. This research provides a qualitative study of existing foreign exchange exposure (transaction, operation, and translation exposure) and current & effective foreign exchange risk management in American and Korean international contractors, as they represent both new and long-time members of the global construction market. Finally, recommendations of techniques for new and existing international contractors to minimize and better manage foreign exchange risk will be offered.