• Land and Housing Review
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• v.8 no.3
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• pp.189-200
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• 2017

The work breakdown structure and the precedence relations by work activity are very important because they are the basic data for estimating the construction duration in the construction work. However, there is no standard to accurately estimate the construction duration since the size of the school facilities construction is smaller than the general construction work. Therefore, some schools are unable to open in March or September and the delay of the construction duration can cause damage to the students. To solve this problem, this study developed a work breakdown structure of school facilities construction work and analyzed the precedence relations by work activities. The work breakdown structure of the school facilities construction is composed of three steps. The operations corresponding to level 1 and level 2 are as follows. (1) 2 preparatory work categories; preparation period and temporary construction. (2) 17 architectural work categories; temporary construction, foundation & pile work, reinforced concrete work, steel roof work, brick work, plaster work, tile work, stone work, waterproof construction, wood work, interior construction, floor work, metal work, roof work, windows construction, glazing work and paint construction. (3) 7 mechanic and fire work categories; outside trunk line work, plumbing work, air-conditioning equipment work, machine room work, city gas plumbing work, sanitation facilities and inspection & test working. (4) 4 civil work categories; wastewater work, drainage work, pavement work and other work. (5) 1 landscaping work categories; planting work. The work breakdown structure was derived from interviews with experts based on the milestones and detailed statements of existing school facilities. The analysis of precedence relations by school facilities work activity utilized PDM(Precedence Diagramming Method)which does not need a dummy and the relations were applied using FS(Finish to Start), FF(Finish to Finish), SS(Start to Start), SF(Start to Finish). The analysis of this study shows that if one work activity is delayed, the entire construction duration may be delayed because the majority of the works are FS relations. Therefore, it is necessary to use the Lag at the appropriate time to estimate the standard construction duration of the school facility construction. Lag is a term used only in the PDM method and it is used to define the relationship between the predecessor and the successor in creating the network milestone. And it means the delay time applied to the two work activities. The results of this study can reasonably estimate the standard construction duration of school facilities and it will contribute to the quality of the school facilities construction.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.213-221
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• 2022

Defects are the risk factors in the construction process of buildings. They cause damage, delaying the construction duration. They especially cause adverse effects on the top-down construction method. This study analyzed the degree of construction delay induced by each work type, focusing on defects in the top-down method. Then, we derived construction delay induction coefficient from different work types in order by using the severity of construction delay per defect and the occurrence probability of defect; this assessment model measures the impact of defects on construction delay for each work type. Furthermore, by comparing each work type based on the defect frequency and the construction delay induction coefficient, we found work types that need to be administered attentively. We identified that plastering work was easy to overlook, requiring caution in defect management. This study provides an efficient defect management system suitable for the buildings that are built using the top-down construction method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.251-252
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• 2015

Enough school facility maintenance data should be accumulated in a database or data warehouse in order to supply information about school facility correct maintenance budget plan, budget assignment, and cycle and rate of maintenance or replacement. For those, this research analyze the present school facility maintenance practice and budget and construction cost structure. In order to solve the problems, this study analyze the present practice of maintenance and replacement and obtain LCC(Life cycle cost) data, perform expert interview and then establish construction work breakdown structure of maintenance of educational facility by combining work breakdown structure(WBS) and cost breakdown structure(CBS).

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1048-1052
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• 2005

In Korean cases, the occupation of building construction is below 10% of the total industry workers but from a accident rate point of view, it is a risk serious industry and it's hazard is very considerable which accident rate is up to 30% of the total industry workers. The reason of high accident rate of the building construction is its own characteristic, hazard of the work in which is implicated and the shortage of safety counter plan and information, so it is most required to the building construction that educating, training, short and long period approaching to prevent the hazard. The safety information of building construction which is related to safety accident is divided into human and material such as hazard, work situation, cause and counter plan. The existing hazard cases imply all of the information about the work type and work progress of the building construction, so if the research of the every fact is well accomplished, we can obtain the useful information and prevent the hazard of building construction. From this point of view, the emphasis of this study is based on analyzing the cause of hazard first, suggesting the safety information each part of work type and work progress second, and finally making the all existing hazard cases to the Data Base and developing the safety information system.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.7-13
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• 2013

Recently, defect management have been considered as one of the major issues for more large-sized and complicated in domestic construction industry. However, the defect management have not been performed systematically because of special manpower, excessive amount of documents, 2D based inspection work, unclear traditional checklists, complicated work process and difficulty in communicating construction information. Therefore, the construction field manager could not performed the quality inspection and defect management work on time as well as the reliability of recorded quality and defect factors was decreased. The primary objective of this study is develop a Construction Defect Management Application CDMA) using a mobile (smartphone). The application can be sharing a huge information and communication technology based on RFID (Radio-Frequency Identification), BIM (Building Information Modeling) which enables field mangers to efficiently gather the information of defection in construction on-site.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.786-790
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• 2005

As the scale of building construction is larger and more complex and the adaptation of new technology is increasing, the tendency of the risk serious accident cases is increasing now. Especially, the accident rate is below 10% at the building construction workers in Korea but among the total industrial accidents it exceeded by 35%. To prevent a construction accident, it is essential that not only to have a through grasp of the characteristic of safety problem but also to establish of efficient safety counter plan are required. According to the type and situation of building construction, the acquirement of necessary information is useful to prevent the hazard of work and establish the counter plan. Among the safety information it is a thing of especial importance that to estimate the hazard of work types for building construction to prepare the counter plan of safety. This study will analyze all of the1600 accidents of the building construction works from the data of KOSHA(Korea Occupational Safety &Health Agency) which were collected during 11 years(1992~2002) data relating to serious accidents of the building construction works, and suggest the counter plan according to the each work type in building construction works.

• Journal of the Korean Society of Safety
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• v.26 no.3
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• pp.34-42
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• 2011

Death disaster among the disasters in construction field is mainly occurred by crash, and the work plate is the main objects causing crash. This study was performed by interview with workers in construction field to evaluate the consciousness on safety and to analyze the type of use and the state. Finally the problems while using work plate were appeared with its requirements for the improved use. Based on the results from this study, amendments were proposed for some parts of regulation related, and further four types of development on the safe work plate were presented. It is expected that the safer construction environment could be composed by using the results.

• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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• pp.119-125
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• 2005

Construction work accidents have not decreased in spite of much effect such as new work methods education and research related to the safety management. Specially, many fatal accidents were mainly caused by unanticipated risk factors in reinforced concrete construction work, which was involved in apartment, building. school church, hotel hospital, bank work and the other works. According to the construction fatal accident book by KOSHA 1,903 workers were killed by the fatal accidents in reinforced concrete construction work during the 13 years$(1992\~2004)$. From these reasons, this study researched the cause of fatal accidents which were happened in reinforced concrete construction work during last 13 years and surveyed construction managers and specialists about risk factors according to the work type in the reinforced concrete construction work. Therefore, this study will suggest the counterplan about the construction safety management and prevent fatal accidents from construction site related to the reinforced concrete construction work.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.31-37
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• 2011

Construction automation is yet to be improved since construction site still faces a lot of high risks and difficulties. This research focuses on applying robotic beam assembly system in place of construction workers. This system consists of CF (Construction Factory) structure to provide adequate working environment to robot automation. The CF structure not only gives automation environment for a robot but also houses the equipments to protect from outside effects. The robotic beam assembly system also consists of robotic bolting system and robot transport mechanism. It utilizes various tools to insert and join the bolts and nuts. Visual servoing helps precise robot motion by sensing bolt hole and tail of the bolt. ITA system helps non skilled workers to easily perform the assembly work with the robot system. The robot transport mechanism includes sliding rail and cross-wired lift. It carries the robot to a desired position for assembly work.

• Land and Housing Review
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• v.10 no.3
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• pp.77-87
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• 2019

In Korea, the modular construction method was applied to the construction of facilities such as military barracks and school dormitories, beginning with the pilot project of Seoul New Elementary School in 2003. In 2017, public modular houses were supplied to Busan(Yongho-dong) and Seoul(Gayang-dong), and modular housing is expected to continue to be supplied in the future. However, there is no clear construction standard for the modular housing construction yet, and there are few cases where the infill modular system is applied. Therefore, this study established the work breakdown structure and proposed a standard process focusing on the infill modular system applied to the construction of Dujeong-dong modular house in Cheonan. Level 1 of the work breakdown structure by construction stage of Infill modular was defined as modular manufacturing, assembly, and finishing process. Level 2 was defined as preparation, modular production, modular infill, modular fixing, floor plastering, building finishing, and other site finishing. Level 3 is defined as 57 detailed unit work of infill modular construction. The standard process of infill modular is proposed for the assembly stage that is commonly applicable to infill modular housing construction. The results of this study can be used for the process plan, transportation plan, lifting plan of modular housing construction.