• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.3-10
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• 2019

The entire duration of the long-term continuous construction contract project cannot be expected when calculating the initial budget as the construction of the contract is carried out annually according to the budget composition. In addition, the statutes related to the defect liability and execution of contracts have not been established systematically in relation to the contract. Therefore, there are many problems at the actual construction site with regard to the defect liability or the performance of the contract in relation to the contract. In this study, the following improvement directions were presented for the efficient operation of the contracts: First, the defect liability is legal and should be specified in an Act rather than an enforcement decree. Second, if the parties to the contract vary in the following order in the contract, the special agreement should be specified in the enforcement decree. Third, in the event of an indirect cost due to the extension of the period of the long-term continuous work, the contingency items of the total project cost management policy should be utilized. Fourth, in the case of general construction contract conditions, clauses related to the purchase of the premium of the CAR, inspection, taking over, defect repair, and defect inspection shall be supplemented.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.205-211
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• 2005

Turnkey projects accounting for some $10\%$ of the total volume of the projects in the domestic market have been often implemented without the process of full-scale review or study because of clients' lack of expert and expertise. Moreover, many projects have been executed under the terms and conditions of the contact which were found to be unilaterally in favor of the clients. The study, as part of effects to mitigate the claims that would possibly be caused by the potential problems with the typical turnkey projects, were intended to identify the elements of the claims virtually being occurred at the construction sites, and then analyze the degree of influence on the project so as to be able to incorporate the outcome into the plan at the working-levels. As a result of experts' review, through the survey, of the elements once extracted, those having relatively higher degrees of influence on turnkey projects were determined, and the investigation aimed at estimating the amount of claims in terms of value were conducted to eventually identify, evaluate and verify the elements that had affected the Project together with the degree of influence.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.185-193
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• 2008

In order to improve work efficiency in high-rise apartment building construction, it is required to establish the major criteria and practical method for selecting the construction lifts. It is necessary to analyze work efficiency and economic feasibility depending on speed, size and capacity of lifting equipment and characteristics of construction projects. The purpose of this research is to develop the fundamental process and information for selecting the lift in order to plan and manage the material lifting and laborers' vertical transporting in the high-rise apartment building projects more effectively. In order to satisfy the objective of the research, work performance of the lifting machines with different speed and carrying capacity is analyzed under the practical constraints. In addition, potential economic evaluation is conducted. One of the significant findings of the research is that the mid-speed lift shows 43% improvement in work efficiency compared with the low-speed lift. The results of the research will be used as the basis for developing the further optimal lifting management system.

• Journal of the Korea Institute of Building Construction
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• v.11 no.2
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• pp.116-126
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• 2011

Recently, eco-friendly energy has been employed in diverse fields of industry in order to reduce environmental pollution and secure a new growth engine. In particular, practical applications of photovoltaic energy, such as building integrated photovoltaic systems, have been implemented to the construction industry based on the extensive interest in photovoltaic power as an unlimited and sustainable energy. While the construction of a high-rise building requires large amounts of energy, methods of reducing energy consumption in the construction phase have rarely been studied. Based on this motivation, the research proposes a photovoltaic based formwork system (PVFS), and then performs a design and feasibility analysis for its application to the construction of a high-rise building. Using a case study, the research implements various analyses, including area, position, and total allowable weight required by PVFS, and evaluates the influences of PVFS on the construction processes, as well as its economic feasibility. The proposed PVFS can be adopted to a real-world project in the near future, depending on the advancement of technology and economic feasibility. The results of this research will contribute to establishing a construction environment that promotes a reduction of energy consumption by using eco-friendly energy in the construction phase.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.71-80
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• 2011

Flying net should be installed on every 3 or 4 construction floor from 8m above ground according to the rule. In the apartment housing construction, flying net installation work has been recognized the most dangerous work among the whole works because a small mistake of labors might make their death accident. Sub-contractors specialized in flying net have been developing various flying net types. However, most works of installing flying net as working with the developed system are performed outside the apartment housing, so that the risk of fall in works of installing supports and unfolding net is still high. Furthermore, as using the previously developed flying net labors might bump into the frame or the wire rope for supporting so that it makes secondary accidents. The objective of this research is to produce the proto-type of anti-collision flying net system based on the result of problem analysis on the installation and detachment process and suggest the improved anti-collision flying net system, which is able to improve safety and field applicability by conducting field experiment and analyzing performance.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.597-601
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• 2006

There are considerable amount of man power and time spent for analysis and selection of various materials due to the inadequate application system and rapid searching process of material related information in each stage of building production process. Also, due to the insufficiency in recycling system of important information created for each process, they are hoarded at each task stage and project completion. As a result, because of the repetition of the similar/identical tasks on each process, it is the major reason for impeding the efficient employment of manpower of the company and decreasing competition of the company. Moreover, in selecting finish material in the project field, there are many difficulties due to the lack of technical information such as product characteristics and field applications. The construction quality also affects the profit and loss of the product which calls for a need to develop continued information management system that the finish material related examples could be shared in real time. The objective of this study is to propose a building finish material information which the real time research and application is possible to raise the productivity. TO do this, the current material information task status analysis and questionnaire research should be conducted to understand the demand of system development and reflect the result onto the system for easy access and application. Therefore, the building finish material information system for enhancement of productivity of construction task proposed in this study is expected to be utilized in enhancement of construction quality, maximization of company profit, and strengthening of company competition.

• Journal of the Korean Geotechnical Society
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• v.25 no.8
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• pp.33-45
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• 2009

The conventional single-core PBDs have been widely used in order to accelerate consolidation settlement of soft grounds. When using the single-core PBD in a thick clay deposit, a delay of consolidation may occur due to high confining pressure in the thick deposit and necking of drains. This study is to compare the performances of soil improvement by the single-core and double-core PBD installed at a site in Busan New Port which exhibits approximately a 40m-thick clay layer. An in-situ test program was performed at the test site where a set of the double-core PBDs and single-core PBDs were installed to compare the efficiency of each drain. In addition, the discharge capacity of each PBD has been measured using the modified Delft Test. A series of laboratory tests for estimating in-situ soil properties have also been performed in order to obtain input parameters for a numerical program ILLICON. The discharge capacity of the double-core PBD is higher than that of the single-core PBD in the modified Delft Test. However it is observed from the comparative in-situ test and numerical analysis that there is no difference in the performance of ground improvement between the two drain systems. This discrepancy comes from the fact that the amount of water released during consolidation in most common field conditions is much smaller than the capacity of even the single core PBD. And thus, considering actual field conditions, it can be concluded that the single-core PBD has enough discharge capacity even in the thick clay deposit such as this test site.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.628-633
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• 2008

Tall building construction has been increasing due to the need to maximize land usage. It causes the increase of vertical transportation for workers and materials, which significantly affects the productivity and lifting planning, therefore, has to be made carefully based on the characteristics of the field. However, the existing method to calculate the number of lift is too simple to consider complex and various characteristics in tall building construction. Accordingly, we developed the model for selecting the best system of vertical transportation by using Queueing theory. To find out the situation of the queue of resources such as material and workers, a simulation program will be applied.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.97-104
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• 2007

Recently, the demand of the large span structures has been increasing. The large span structures include such a large scaled structures such as: the shell structure, the space frame structure, the membrane structure and the cable structure, etc. The large span structures are supposed to be confirmed and issued carefully at the initial process of the design besides the construction engineering aspects because of the structural specific cause that should solve and accomodate those large and wide space without columns. In the field of the large span structure construction, the erection construction method has been regarded as a major affected aspects on the construction cost, construction term, and stability. In the field of the large span structure construction, there are various construction method and system could be applied depends on the condition of the construction site and other circumstances such a major construction method as: the element method, the block method, the sliding method, the lift-up method and complexed method, etc. In this study, as the case study of the erection construction method of the large span structures, after survey and study that those existing large span structures construction cases which had applied and adopted the election construction method and analysis and classify into the Uoups by the size, span, ceiling height, structural system in odor to supply and suggest the data for the enhancement and development in the field of the erection construction method as a efficient structural solution of the large span structure construction.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.561-569
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• 2014

In construction site, BIM is used in part of construct-ability review and design mistake checking. However, in a current domestic construction site, except public order project, most of work in private order project has been processing based on 2D work. As an expert resists to certain point in introduction of new technique, it may be shown in the introduction of BIM. For this, We need to analysis construct-ability of introducing BIM, work field of introducing and operational capability about present domestic construction engineers. Therefore, this study solves the problem of existing construct-ability analysis, and it visualizes the various information and objects for an effective job performance. Furthermore, construct-ability analysis by BIM that can use an intergrated management is theoretically examined and practical field-application priority among conclusions is proposed through a survey targeting on the hand-on worker. Therefore, this study suggests a factor supplying for a business-centric introduction plan and support condition.