• 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.

• Geomechanics and Engineering
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• v.28 no.1
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• pp.65-75
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• 2022

Time and cost of construction are key factors in decision-making during a tunnel project's planning and design phase. Estimations of time and cost of tunnel construction projects are subject to significant uncertainties caused by uncertain geotechnical and geological conditions. The Gaussian Process Regression (GPR) technique for predicting ground condition and construction time and cost of mountain tunnel projects is used in this work. The GPR model is trained with data from past mountain tunnel projects. The model is applied to a case study in which the predicted time and cost of tunnel construction using the GPR model are compared with the actual construction time and cost for model validation and reducing the uncertainty for the future projects. In addition, the results obtained from the GPR have been compared with to other models of artificial neural network (ANN) and support vector regression (SVR) that the GPR model provides more accurate results.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.26-35
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• 2020

Tunnel construction is an important part of Korean public construction projects. Although the development of various equipment and technologies has led to advances in tunnel construction methods that are implemented on sites, the cost standards related to such works do not yet reflect the realities of the construction sites. A literature review and site surveys were conducted to suggest reasonable cost standards for tunnel work that reflects the realities of the field. First, each item in the cost standards for tunnel work, as established in the Construction Standard Production Rates, were analyzed. The results were compared with the actual costs implemented on tunnel projects. The key items analyzed included those regarding the work cycle time, such as rock classification, profiling survey, drilling speed, and muck-disposal processing equipment combination, as well as the number of people put to tunneling work. Based on the site survey results, improved estimates regarding the cycle time per one tunnel drilling blast, drilling speed of the machine, muck disposal processing equipment combination, and the number of people put to tunneling work were suggested. This study suggests the cost standards that reflect the realities of tunneling sites. The results are expected to help ensure adequate costs for tunnel construction projects.

• Journal of the Korean Society of Safety
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• v.30 no.5
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• pp.29-36
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• 2015

Common utility tunnel is essential to the daily lives of people underground utilities (electricity, gas and supply facilities such as water, communication facilities, sewer facilities, etc.) to improve the appearance by co-acceptance and disaster prevention, important for the conservation of the city's population was concentrated road construction the city-based facilities. There is recognition of the importance of the various supply treatment facilities in common utility tunnel as infrastructure to accommodate joint according to the city expanded, the demand for infrastructure. In this paper, a cost-benefit analysis using a one-time occurrence, without simply relying on cost or current cost, project manager for the city-dimensional feasibility study conducted, the user level of the maintenance costs and user costs, including social costs items from various angles can be investigated and proposed a mechanism of economic feasibility common utility tunnel. Evaluation of the proposed technique is cost-benefit and cost caused by installing common utility tunnel the existing pipeline area - was investigated by the benefit analysis, extended and repeated common utility tunnel installation depends much affected by the excavation, so users of reducing the number of repeat excavation convenience can be seen that this occurs.

• Explosives and Blasting
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• v.19 no.1
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• pp.11-18
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• 2001

This is a case history on design and cnostruction of tunnel for under passing an underground transformer substation. The original construction plan was cut & cover method to avoid blasting vibrations and displacements of facilities during the construction stages. But this plan was changed to tunnel because of the difficulties from construction period, cost and the required relocation site. As a results of tunnel construction, the relocation of transformer substation and replacements of transmission cables were not necessary. Therefore about 10 months of construction period and 3.5 billion wonts of construction cost were saved. Additionally, quantitative criterion for blasting was provided through the results of blasting vibration analysis.

• Geomechanics and Engineering
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• v.28 no.4
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• pp.421-435
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• 2022

The necessity of estimating the time and cost required for tunnel construction has led to extensive research in this regard. Since geological conditions are significant factors in terms of time and cost of road tunnels, considering these conditions is crucial. Uncertainties about the geological conditions of a tunnel alignment cause difficulties in planning ahead of the required construction time and costs. In this paper, the continuous-space, discrete-state Markov process has been used to predict geological conditions. The Monte-Carlo (MC) simulation (MCS) method is employed to estimate the construction time and costs of a road tunnel project using the input data obtained from six tunneling expert questionnaires. In the first case, the input data obtained from each expert are individually considered and in the second case, they are simultaneously considered. Finally, a comparison of these two modes based on the technique presented in this article suggests considering views of several experts simultaneously to reduce uncertainties and ensure the results obtained for geological conditions and the construction time and costs.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.1-15
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• 2008

Recently, because of the various factors by uncertainty of underground, the risks in tunnelling have been occurred increasingly. Therefore, it is very important to estimate and control the risks considering geotechnical conditions for tunnel stability and environmental problems by tunnel construction. In this study, the risk analysis for tunnel stability was carried out by classifying the risk factors such as ground support capacity, ground settlement, the inflow of groundwater into the tunnel and the damage by the earthquake. Also, the risk assessment for the environmental problems was performed by calculating the vibration and noise by blasting and the drawdown of the groundwater level caused by tunnel construction. Each risk factor was evaluated quantitatively based on the probabilistic and statistic technique, then it was analyzed the distribution characteristic along overall tunnel site. Finally, it was evaluated that how much each risk factor influences on the construction cost with a period for tunnel construction, so it is possible to perform reasonable tunnel design which was capable of minimizing the risks in the tunnel construction.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.459-472
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• 2015

A recently developed tunnel section enlargement method can maintain traffic flow during construction by using a protector. By keeping traffic flowing, it can minimize the lost time and costs associated with diversions and also the accompanying environmental pollution. On the other hand, installing the protector can lengthen the construction period and increase the direct cost. This paper presents a method for analyzing the economic feasibility of tunnel section enlargement methods considering the direct construction cost and the indirect social cost. The indirect costs are divided into categories of: vehicle driving cost, travel time delay cost, and environmental pollution cost. The economic efficiency of existing technology is compared with the new method in an case study of Namsan Tunnel 3.