• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.93-104
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• 2008

study deals with the reliability assesment for the 5-year phases of a suspension bridge construction in Korea. The main objectives of this study are; (1) the evaluation of the reliability of a suspension bridge by considering an ultimate limit state for the fracture of main cable wires, (2) the determination of the critical phases among 28 construction stages for the deck erection, and (3) the evaluation of the reliability of the limit state for the erection control during construction stages. The research and the design of the suspension bridge have been focused on the state of construction mainly based on empirical data. Based on the recent survey of the distribution of accidents in Korean railways, over 80% of the accidents related to the uncertainties in human error, planning, design, materials and loads during construction have ben reported before the completion of construction. While many researches have evaluated the safety of bridges, the uncertainties in the construction phases have not been well treated in a guidelines or a specifications. An improved adaptive response surface method is used for the risk assessment in the construction phases of the target suspension bridge.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.535-540
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• 2001

In the early construction phase of the Korea Train Express (KTX), the Movable Scaffolding System (MSS) for the top structure of the bridge was the predominant construction method. But the method had to be changed due to arising problems and an alternative method had to be found. Company H that participated in Korea Train Express construction project achieved excellent results of performance through the introduction of the Precast Span Method (PSM), which has been previously successfully employed in foreign express train projects. This study intends to verify the superior performance of PSM over MSS in the KTX construction process by conducting a comparative analysis on PMS and MSS based on the field experience of company H. This study will not only help to understand PSM, which is expected to expand its future scope of application, but also contribute to solve the problems of PSM that occurred during the construction phase.

• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.459-469
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• 2020

The purpose of this study is to secure the same or more structural performance and constructability for the detail off hooks cross-constructed at 135° used as external-ties standard detail in reinforced concrete columns, therefore, to the purpose of improving constructability, The clip-type binding implement was suggested. the experiment on the constructability evaluation and cost analysis of the clip-type binding implement by 90° end-hooked transverse reinforcement in reinforced conrete columns was carried out. The results of the analysis confirmed that standard detail column took about an one hour regardless of the diameter of tie. When using the clip-type binding implement, It was reduced to about 50% of the standard detail column. and regardless of the building size, it was most effective for the cost down when using the clip-type binding implement 1ea, it was about 32% fo labor cost reduction effect in comparison with using standard detail. as a result, Using the clip-type binding implement is shown be very effective in the working time and construction cost reduction.

• Magazine of the Korea Concrete Institute
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• v.9 no.5
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• pp.127-135
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• 1997

This paper is an experimental study of the acid-resistance of concrect which contains silica sand particles. In the concerete sample experiment. the workability and strengh as well as the acid-resistance of the hardended concrect is inverstigated.

• Journal of the Society of Disaster Information
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• v.8 no.1
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• pp.81-92
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• 2012

In this study, in-depth site investigation related to design and construction of pile foundation was carried out, especially with respect to 103 large-scale bridges located in South Korea. As a result, the depths and location of investigation was unsatisfactory at the foundation investigation process. Moreover, pile load tests were not performed when the capacity of the file is calculated in planning phase, and it was difficult to determine the load capacity limit due to the fact that loading capacity was not specified in pile-loading test. The design criteria related to pile foundation does not reflect the reality of the construction site, and that causes over design, and economic inefficiency in budget. Therefore, the purposes of this study is to review case studies related to the bearing capacity of pile foundations and suggest improvements in the construction specifications.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.78-88
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• 2010

Since the larger and complex construction projects are performed, project performance measurement is highlighting the importance to eliminate inefficiencies and plan to reasonable management practices. So many researchers are conducting research about the project critical sucess factor. But, these factors are mixed both management practices to improve performance and native project characteristics. Therefore performance measurement data couldn't apply to another project successfully. And the project characteristics affect project performance. But contractor couldn't change characteristics. This study provides a project characteristics's definition and classification. This study provides a quantitative level of performance improvement difficulty through out project manager survey. The contractor can estimate a level of performance difficulty through initial project information. With this, project contractor can more efficiently manage project.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.469-475
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• 2022

As the recent structure construction is constructed as a large-scale and deep underground excavation in close proximity to the building, the installation of retaining wall and supporters (Struts) has become complicated, and the number of supporters to avoid interference of the structural slab has increased. This construction process becomes a factor that causes an increase in construction joints of a structure, leakage and an increase in wall cracks. In addition, this reduced the durability and workability of the structure and led to an increase in the construction period. This study planned to dismantle the two struts simultaneously as a plan to reduce the construction joints, and corrected the earth pressure by assuming the reaction force value by the initial earth pressure and the measured data as the response ratio. After recalculating the corrected earth pressure through the iterative trial method, it was verified by numerical analysis that simultaneous disassembly of the two struts was possible. As a result of numerical analysis applying the final corrected earth pressure, the measured value for the design reaction force was found to be up to 197%. It was analyzed that this was due to the effect of grouting on the ground and some underestimation of the ground characteristics during design. Based on the result of calculating the corrected earth pressure in consideration of the response ratio performed in this study, it was proved analytically that the improvement of the brace dismantling process is possible. In addition, it was considered that the overall construction period could be shortened by reducing cracks due to leakage and improving workability by reducing construction joints. However, to apply the proposed method of this study, it is judged that sufficient estimations are necessary as there are differences in ground conditions, temporary facilities, and reinforcement methods for each site.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.85-88
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• 2011

MRS(Multi Ribbed Slab) method was developed to accomodate Korean construction practice and needs of Korean customer. By means of 4story-1piece column and MRS method, we achieved construction cost cut down and reduction of construction period.

• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.227-234
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• 2013

In this research, early strength development performance of early strength improvement type ordinary cement which is economically feasible early strength cement(Type III), improved early strength ordinary cement(Type I), was estimated to derive minimum curing temperature and proper water to cement ratio according to cement for early strength development through examination of fresh concrete properties and compressive strength according to water to cement ratio curing $10^{\circ}C$, $15^{\circ}C$ and $20^{\circ}C$ to suggest fundamental data for practical use of early strength concrete.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.444-446
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• 2011

3상3선식 2소자 계량방식을 적용하고 있는 154kV 3상4선식 중성점 접지 고압 고객은 상 불평형시 계량오차가 발생하게 된다. 상 불평형시의 3상4선식 정상 계량방식과 3상3선식 계량방식의 계량오차에 대한 기 공개된 시험분석 자료를 기반으로 하여 본 논문에서는 3상4선식 공급선로에서 2소자 계량을 적용하고 있는 3상4선식 고객에 대하여 전력계량의 신뢰도 향상을 위해 제안된 기존의 3상4선식 전력량계를 활용하여 계량 환경을 개선하는 시공기술로서, 설비개선 비용이 거의 소요되지도 않고 무정전 시공과 함께 전력량계의 제작사양을 변경하지 않는 방법으로 계량 정밀도를 개선 할 수 있는 방안에 대한 검증시험과 적용성 분석 등의 개선대책에 대하여 기술한다.