• Journal of the Korean Society of Safety
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• v.23 no.2
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• pp.87-97
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• 2008

The Ilsun Bridge is the world's longest box girder bridge(801m) with corrugated steel webs and has the widest width($21.2{\sim}30.9m$: tri-cellular cross section) among these kinds of composite girder bridges. It has fourteen spans(50m, 10 at 60m, 50m, 2 at 50.5m) where twelve spans are erected by the incremental launching method and two spans by full staging method. Special topics related to the structural safety of prestressed concrete box girder bridge with corrugated steel web in construction stage and service were reviewed. Investigations focus on the span-to-depth ratio, shear stress of corrugated steel webs and optimization of tile length of steel launching nose. The span-to-depth ratio of Ilsun bridge has been found to be well-planned while the corrugated steel web has been designed highly conservative and it has been observed that the conventional nose-deck interaction equation do not fit well with corrugated steel web bridges. As a result, detailed construction stage analysis was performed to check the stress levels and the safety of preceding design conditions. Finally, from the design review of Ilsun bridge, this study suggests optimal design issues which should be of interest in designing a prestressed concrete box girder bridge with corrugated steel webs.

• Land and Housing Review
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• v.12 no.4
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• pp.93-101
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• 2021

As the number of small households (1 to 2 persons per household) in Korea gradually increases, so does the importance of housing supply policies for small households. In response to the increase in small households, the government has been continuously supplying urban housing for these households. Since housing for small households is a sales and rental business similar to apartments and general business facilities, it is important for the building owner to calculate the project's estimated construction duration during the planning stage. Review of literature found a model for estimating the duration of construction of large-scale buildings but not for small-scale buildings such as urban housing for small households. Therefore this study aimed to develop and verify a model for estimating construction duration for urban housing at the planning stage based on multiple regression analysis. Independent variables inputted into the estimation model were building site area, building gross floor area, number of below ground floors, number of above ground floors, number of buildings, and location. The modified coefficient of determination (R_a²) of the model was 0.547. The developed model resulted in a Root Mean Square Error (RMSE) of 171.26 days and a Mean Absolute Percentage Error (MAPE) of 26.53%. The developed estimation model is expected to provide reliable construction duration calculations for small-scale urban residential buildings during the planning stage of a project.

• Journal of the Korea Institute of Building Construction
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• v.7 no.1 s.23
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• pp.63-70
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• 2007

The aims of this study are to draw the project risk factors by grasping the relation especially between the construction preparation cost calculation and the project risk factors in the project's bidding stage, and to draw the cost estimate based on the risk when the orderer or the constructer performs the project and the main factors in calculating the most suitable construction cost by clarifying the understanding degree of the influence between the risk factors and the construction cost. In addition, this study can give a help to the proper decision -making through the prediction of the construction preparation cost, and this study is expected to give the basic data in developing the assessment tool for the most suitable construction cost of the project.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.319-324
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• 2003

There is much more possibilities of encounter of critical problems and uncertain factors in construction project it is very important to analyze various risk factors of the project in its first stage. Because of the uncertainty, we need to study about the construction insurance scheme for risk-transfer within construction management method. This research methodology has been devised through analysis of characteristic of classified domestic construction insurance as well as some related foreign insurance system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.14-15
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• 2019

In this paper, it was tried to prove the possibility and effect of coordinate measurement by using MEP layout equipment at the construction stage, and to propose a method to improve measurement accuracy during construction. For this study, the passenger terminal site, which is a long span structure, was selected and compared with three dimensional CAD drawings and construction measurement results using MEP layout equipment for the precise construction of long-span irregular curved roof layers. As a result, it was found that it is possible to construct three-dimensional curved roof layers using MEP layout equipment through measurement and analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.215-216
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• 2023

As the introduction of new climate system, efforts to change carbon neutrality, efforts to convert carbon neutrality. In Korea, we are setting up carbon emissions through greenhouse gas and energy target management system for business and companies that emit carbon emissions. The construction industry quantitatively predict the carbon emissions, but it is struggling to set up the amount of carbon emissions before construction stage, but it is suffering from lack of data. Therefore, this study was conducted by collecting data on the energy usage amount of carbon emissions according to the energy usage of the construction phenomenon and low-capacity prediction of the construction phenomenon. Through collected data, the average energy usage amount by building users and evaluated the average carbon emissions. It also evaluated the contribution of carbon emissions by energy sources.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.164-173
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• 2005

In this paper, the systematic problems of safety management in domestic construction industry are presented by the investigation and analysis of construction fatal injuries. In particular, it is discussed that the current construction safety management system by contractors leading is ineffective to prevent the serious accidents caused by inappropriate planning and design and to circulate the safety management cycle without interruption. A couple of ways for improving domestic construction safety management system are suggested in broad perspective. This is done by the analysis of construction safety management system of four advanced industrial countries such as the United States, the United Kingdom, Germany, and Japan and the study of a best practice. Total safety management system by owners leading is recommended to prevent construction accident effectively because this system makes all the parties join to the management system and distribute the responsibilities clearly to each party. This will drop the accident occurrence rate by dragging all the parties' cooperations and activating the total safety management system in an early stage.

• International Journal of Fluid Machinery and Systems
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• v.9 no.2
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• pp.107-118
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• 2016

This paper focuses on the single stage and multistage performance characteristics of centrifugal mixed flow submersible borewell pump. This study reveals that the performance of single stage pump is higher than that of multistage pumps. The head, input power and efficiency of single stage pump are higher than the per stage head, per stage input power and efficiency of multistage pumps. This study is divided into three parts. In the first part, five prototype pumps were made in single stage and multistage construction and the performance tests were conducted. In the second part, numerical validation has been done for different turbulence models and grid sizes. k-Omega SST model has been selected for the performance simulation and was validated with the performance of the test pump with static pressure tappings. In the third part, single and three stage pump performance were simulated numerically and compared with experimental results. The detailed analysis of pressure and velocity distributions reveals the difference in performance of single and three stage pump, due to non-uniform flow and difference in averaged flow velocities at the subsequent impeller inlets except the 1st stage impeller inlet.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.218-219
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• 2014

The selection of an appropriate contract method is vital for the successful operation of the project. However, there has been a lack of studies on objective decision making support models for use in the planning stage of a project contract. The present study had the goal of analyzing the factors that influence contract method selection, as an initial study for developing a project contract method selection model. The existing related studies were analyzed, and the factors considered in the literature were selected. Then, based on the findings, the opinions of an expert group on the important factors for contract method selection were collected through a survey. The collected opinions were analyzed using factor analysis, a statistical analysis method. The results will be utilized in the future as preliminary data for developing a decision making model for selecting a contract method.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.273-280
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• 2001

In architecture, each project participant must maintain organic relationship with others. However, current practices are rather procedural and discrete than organic, which result in considerable inefficiencies. The cool-downs of Korean construction market also force the architects to be familiar with the new construction methods and systems. This research mainly focuses on the pre-development stage of such systems, analysing relationships between the information of architectural design and other parts of construction information like structure, construction, environment, and so forth. The result of analysis can be organized into attributes of members in a physical building, which can be modeled in a 3D system. The resulting model can be used for automated generation of drawing, Bill of Materials, finite element meshes for structural analysis and energy analysis, etc. by extracting meaningful information from it. Hence, the purpose of this research is to analysis the relationship among domain-specific information (e.g. structural engineering, construction detail, energy evaluation) that are represented in drawings, and to represent the attributes of the information relevantly so that they can be applied to each unit task that forms the whole project. Therefore, an object oriented methodology is introduced to compose design informations in three dimension, and expressing properties of building factors and materials, and to construct a database for computers to recognize architecture informations.