• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.665-675
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• 2008

The objective of this paper is to provide an approximate cost estimating model for tunnel that can be utilized both in quick construction cost estimating for design alternatives, and in evaluating efficiently the cost effects according to the environmental changes during design and construction stage. To meet this requirement, this study analyzes critical cost factors influencing tunnel construction costs. The cost factors include 7 elements such as rock drilling method, advancing method, type of detonator, loader capacity, unit weight and soil volume change factor, length of tunnel. This paper investigates the cost variance according to the change of the cost factors. The result is expected to be used in formulating approximate tunnel cost estimating model.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.677-684
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• 2008

The paper provides an approximate cost estimating model that can be used for tunnel. Based on the previous study analyzed critical factors that have impact on tunnel construction cost, this paper establishes a cost variance index table that reflects the cost impacts due to the change of the critical cost factors. An estimating procedure is described utilizing the index table. For the verification of the suggested model, the comparison of the estimated construction cost with real project cost is performed. The estimated results range from 95%~111% of the real project costs. As an approximate tunnel cost estimating model, the model can be utilized to quickly estimate tunnel construction costs based on the conceptual information at the planning stage and to efficiently make a decision on design alternatives.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.585-588
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• 2007

This study attempts to analyze estimating process and the level of information performing literature review and questionnaire and identify phased influence factors on construction cost using phased information of project and suggests framework of approximate estimation model at the planning and design stage. This paper suggests phased influence factors on construction cost and framework of approximate estimation model for integrated project cost management.

• Journal of Korea Port Economic Association
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• v.28 no.1
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• pp.25-52
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• 2012

In order to solve the current problems and inefficiencies within the Port Authorities(PA) in Korea, this study introduces the concept of the integration of PA and analyses the intention of integration. This study is based on analysing the surveys participated by the members of PA. The surveys consist of six main factors which could influence the intention of integration of PA; contribution, autonomy, strategic factor, financial factor, marketing factor and environmental factor. The two main implications from this study can be categorised as follows. First, this study identifies the structural problems such as regional self-centredness of PA, obscurity of organisations' roles and their rights, limitations on diversification of business and restrictions within PA. Second, this study extensively discusses the option of improving the inefficiency whilst maintaining the current system or to switch to the integration of PA. In addition, it has been found that individual PA recognise the little need for integration. Since the results show that the strategic, financial, marketing and environmental factors would cause both significant and little significant impacts, it would be too haste to decide on a conclusion. However, it is possible to say that the rapid integration of PA can neither improve the efficiency nor improve the characteristics of each region. Therefore, the significance of integration of PA must be further discussed from many different perspectives. The results of this research will serve as a basic literature for further studies on the integration of PA in Korea. Moreover, the problems that have been identified and analysed in this study will contribute to establishing the strategy for further development of PA in Korea.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.176-184
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• 2007

Recently, in the korean construction industry, the importance of cost management in the building design process has been grown up institutional systems and policies for the cost management of design stages are however weakness. Traditionally, the range of cost management has been limited to the construction stages, and due to inefficiency of the infrastructure such as standards and building cost data for cost management. It has trouble to perform the cost management in building design process. This study intends to derive key influence factors for raising efficiency of cost management. With questionnaire surveys to professionals, we analyze a current situations and the influence of obstacle factors on cost management. Finally, the key influence factors are induced, based on the result of the analysis on influence the obstacle factors.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.495-506
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• 2021

A Conceptual cost estimate, which is computed in the preliminary step of a project, is important for decision-making by a contractor in terms of the project budget, economic feasibility and validity analysis, and alternative comparisons. Therefore, a high error rate of a prediction model for a conceptual cost estimate can lead to various problems including excessive project expenditures and a delayed break-even point. this study proposed optimal impact factors by configuring quantitative impact factors computable in a preliminary step in various cases(combinations of impact factors). subsequently, the accuracy of different cases was comparatively analyzed by using the cases as input values of a prediction model using regression analysis. when the optimal combination of impact factors proposed in this study and other combination of impact factors were applied to the prediction model, the regression analysis-based prediction model exhibited 0.2-4.7% improvements in accuracy, respectively. the optimal combination of impact factors proposed in this study improved the accuracy of the prediction model of a conceptual cost estimate by removing unnecessary impact factor.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.468-475
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• 2012

Construction cost of tunnel is decided on construction area, site conditions, and construction methods. However, there is few research on developing models to estimate early construction costs. Therefore, this paper presents a model for early estimation tool for NATM tunnel using system thinking. The effect factors for tunnel construction cost were defined and the causal map is developed. Then empirical case analysis were performed to identify the cost difference due to tunnel length, excavation volume, and rock quality. The proposed model would be an alternative to estimate early construction cost of NATM tunnel.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.445-448
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• 2008

This study attempts to estimate approximate cost on construction of PSC BEAM Bridge using Case-Based Reasoning and suggests approximate estimation model at the planning and design stage. This paper suggests phased influence factors on construction cost and approximate estimation model for integrated project cost management.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.485-490
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• 2003

Nowadays the rapid change in construction environment getting more globalized and complicated has caused lots of unexpected risks from inside and out of the country, so more sophisticated construction management strategies are being strongly needed. This paper suggests a risk management model with which we can estimate the appropriate contingency by quantifying the amount of probable risks immanent in large construction projects, which have a high degree of uncertainty in the anticipation of the total construction cost. To develop the model, the risk factors that make cost variations are elicited based on the real data of the contingencies assigned to the past projects. Furthermore, the influential relationship of risk factors is structured by applying the CRM(Cost Risk Model) which is the synthetic model of Monte Carlo Simulation, Influence Diagram and Decision Tree. The ultimate outcome of this research can by validated by tile case study with a large construction project performed.

• Korean Journal of Construction Engineering and Management
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• v.8 no.2
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• pp.109-117
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• 2007

The construction environment has the trend of oversizing and professionalizing, the increase of the construction period, and the risk factors and the uncertain factors which are important in the construction bid. The misunderstanding and the lack of knowledge of the subcontractor result in the decrease of the profit or the deficit. In conclusion, these are supposed to give the financial burden to the subcontractor. So, it is very important to predict the construction preparation cost calculation by the risk factors in the bidding stage and to calculate the bid unit cost considering the target profit of the subcontractor in the process of the mutual agreement and performance of the contract. In these points of view, this study analyzes how the importance of the risks influencing the bidding cost calculation affect the construction cost, and this analysis can be used as the basic data to establish the suitable bid strategy of the subcontractor.