• Proceedings of the KSME Conference
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• 2005.11a
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• pp.226.2-226.2
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• 2005

• Explosives and Blasting
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• v.37 no.1
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• pp.34-47
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• 2019

This case study is concerned with the project of the explosive demolition for the DCRE Incheon plant located in Hakik district in Incheon city. The building was severely aging due to the high temperature and sea winds of hundreds of degrees emitted by chimney-shaped steel structures inside the building. Due to this, the concrete of the column and the beam fell off and rusted rebar were exposed, and some of the slabs were severely damaged, making it difficult for workers to access the structure. Therefore, it is not possible to apply a mechanical demolition method in which heavy equipment enters the interior of the building, and an explosive demolition method was applied to allow the building to be demolished without dismantling the internal facilities of the building. The order of blasting proceeded in the order of (1) building ${\rightarrow}$ (2) chimney 2 ${\rightarrow}$ (3) chimney 1. A total of 406 electronic detonators (Unitronic 600) was used to sequentially initiate the explosives installed at appropriate in building and chimneys.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.196-197
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• 2015

In tall building construction, time for transporting form affects formwork duration as plan size has become larger and quantity of inputted form has been increased. Thus, necessity of systematic dismantlement sequence of form has been increased to reduce the duration of formwork. Tabu search has been efficiently applied to solve problem of combinatorial optimization by using tabu list which can improve combination values. Therefore, this study proposes optimization model of dismantlement sequence of table form which has been preferred in tall building construction, to reduce the formwork duration by minimizing time for transporting form.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.814-817
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• 2005

Today recycling has been one of the most important Issues In industry as it is required to save the limited amount of natural resources and to keep the environment green. In spite of many efforts to increase recycling rate in industry, however, the practical solutions are very limited. The difficulties are caused by the existence of many parts made of diverse materials and their inevitably complicated assembly structures to satisfy different needs. This paper represents a study on the disassembly sequence generator system for parts recycling. With disassembly costs and revenues, the optimum disassembly sequence can be found with a linear programming.

• Korean Journal of Construction Engineering and Management
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• v.21 no.6
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• pp.66-74
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• 2020

To prevent incident of demolition work the Building Management Act was implemented to manage demolition work. According to this law, buildings with the scale upper than 500㎡ of floor area are classified as permission to conduct the demolition work, however it may be hard to perform safety management at demolition work. In addition, the risk level of demolition work is varied with related to the structure type. So, the purpose of this study is to suggest the improvements of criteria on demolition work considering building structure types including small-scale structures such as masonry, wooden, and other structure. The research process was conducted by three steps. (I) Application of Building Management Act; (II) Analysis of demolition work by structure types; and (III) Subdivision of permission targets by building structure types. The result of this study, permission ratio was only 10% for total demolition work and 2.43% for masonry. Because the masonry, wooden, and other structure types are concentrated on a floor area of small-scale, the separate criteria of demolition work is need to prevent the accident and fatal incident. Through the results, the decision maker can be utilized (1) For the special building structure types, the criteria of enhanced safety management are applied by referring to the overseas law ; and (2) The demolition work can be considered by the criteria of separate permission in terms of structure types.

• Explosives and Blasting
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• v.36 no.4
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• pp.48-61
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• 2018

This case study is concerned with the project of the explosive demolition for the KOGAS office building located in Bundang district in Seongnam city. Since the office building was a kind of long-span beam structures, a mechanical demolition method using jacking support systems was considered in the beginning of the project. With consideration of the excessive reinforcement cost, uncertainty of safety, and prolonged construction period, however, the original plan was later changed to use an explosive demolition method. For the purpose of protecting nearby buildings and facilities during the collapse process, the explosive initiation sequence was elaborately designed to bring down the building structure towards its front left corner. A total of over 550 electronic detonators (Unitronic 600) was used to sequentially initiate the explosives installed at appropriate columns in the first, second, and fifth floors. To diminish dust production, water bags of small and large sizes were respectively installed at each column and on the floors to be blasted. As such, every effort was exercised to mitigate overall noise, dust, and shock vibrations that could be generated during the explosive demolition process for the office building.

• Explosives and Blasting
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• v.27 no.2
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• pp.12-18
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• 2009

Recently, several cases of destruction of old cylindrical silos by explosive demolition method have been reported. This study deals with the subject concerning the pre-weakening of a cylindrical concrete silo for the application of overturning explosive demolition method. In the past, the pre-weakening operation of structure in explosive demolition has been done by use of some empirical methods. These empirical approaches, however, have possibilities of unexpected accidents. In order to provide a guideline for the pre-weakening of cylindrical silos and similar structures, this paper shows the result of a case study, in which the instability of a silo due to pre-weakening is investigated by a numerical structural analysis before actually conducting pre-weakening and demolition operations.

• Journal of the Korea Institute of Construction Safety
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• v.5 no.1
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• pp.9-16
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• 2023

Gang-foam is used in many construction projects because it is not only precise in terms of vertical, horizontal, and specifications, but also easy to install and dismantle. However, major accidents occur every year due to non-compliance with safety rules and work order, also manuals and checklists currently in use are insufficient. Thirty-seven surveys was conducted by analyzing major accident cases of domestic gang-form construction project and deriving 20 risk factors and 43 check points. Based on the survey, the importance and appropriateness of check points were evaluated. As a result of this study, a checklist was presented, check points were placed in the order of importance based on assembly, installation, dismantling, and lifting of the Gang-form process. The checklist was organized so that workers could comply with safety rules and work order. Through this, it is expected to prevent major accidents and contribute to efficient safety management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.96-102
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• 2007

Welding deformation causes critical problems under construction and in use of steel structures by varying the magnitude of the steel structures and deteriorating mechanic strength. Existing method to construct steel structures in civil engineering needs preassembly process for a part of or the whole structures on a broad space to examine the size of structures inevitably varied in the process of welding (assembly process). It leads to waste of time, space and human efforts, worry of safety accidents with the characteristic of the work to be performed on a high place, and non-efficiency and non-economy by using such supplementary equipments as crane. This paper, to remove the needless preassembly process by pre-estimating welding deformation produced under construction of large steel structures, devises a method modeling welded part for applying the equivalence load method and examines the effects of welding sequence and self weight on welding deformation by the method.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.51-61
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• 2018

This study was conducted to propose regional policy for reducing suicide rate by confirming the change of local suicide rate for 10 years from 2005 to 2015 and the effect of change of local environmental factors influencing the change. The main results are as follows. First, the change of city, county, and province suicide rate in 10 years showed that the suicide rate decreased in order of military district, city area, and district. Second, in the case of economic factors, local suicide rate decreased as the local tax burden per capita increased, and as the financial self - reliance increased. Third, in the case of the social integration factors, the local suicide rate decreased as the ratio of the basic livelihood recipient decreased. In addition, local suicide rate decreased as the number of elderly leisure welfare facilities increased. Fourth, in the case of the social demolition factor, the region where the divorce rate is increased, the depression experience rate is increased, and the region where the rate of one person is increasing, the local suicide rate is increased. Therefore, it is expected that the local suicide rate can be reduced through efforts to improve the economic capacity of the whole region, social integration and reduction of the social disintegration phenomenon in the region.