• Explosives and Blasting
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• v.40 no.4
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• pp.15-26
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• 2022

With the recent increase in old and dangerous buildings, the demand for technology in the field of structure demolition is rapidly increasing. In particular, in the case of structures with severe deformation of damage, there is a risk of deterioration in stability and disaster due to changes in the load distribution characteristics in the structure, so rapid structure demolition technology that can be efficiently dismantled in a short period of time is drawing attention. However, structural deformation such as unauthorized extension or illegal remodeling occurs frequently in many old structures, which is not reflected in structural information such as building drawings, and acts as an obstacle in the demolition design process. In this study, as an effective way to overcome the discrepancy between the structural information of old structures and the actual structure, access to actual structures through 3D modeling was considered. 3D point cloud data inside and outside the building were obtained through LiDAR and drone photography for buildings scheduled to be blasting demolition, and precision matching between the two spatial data groups was performed using an open-source based spatial information construction system. The 3D structure model was completed by importing point cloud data matched with 3D modeling software to create structural drawings for each layer and forming each member along the structure slab, pillar, beam, and ceiling boundary. In addition, the modeling technique proposed in this study was verified by comparing it with the actual measurement value for selected structure member.

• International journal of steel structures
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• v.18 no.5
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• pp.1483-1496
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• 2018

Negligible research has been conducted to date on how to analyse weakened columns, thus safety risks are still involved when structures are weakened prior to demolition. There are various methods available for demolishing steel structures. One of the most effective methods that has been developed involves pre-cutting steel columns at a certain height, so that the least effort can be used to collapse the structure by means of pulling out some of the columns. This paper presents (a) an experimental setup developed to test the capacity of axially loaded weakened columns, which is used to (b) validate a finite element (FE) model. The two pre-cuts that are presented in this paper are (1) the double window cut and (2) the triangular window cut, which are both commonly used in industry. A column weakened with a double window cut or triangular window cut reduces the axial load capacity by up to 50 and 40%, respectively. The FE models developed predict the axial failure load of weakened columns for a double window cut and triangular window cut are generally within an accuracy of less than 8 and 10%, respectively. It is shown at higher slendernesses the influence of column cuts is less than would be intuitively expected because global buckling becomes dominant.

• Explosives and Blasting
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• v.29 no.2
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• pp.1-12
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• 2011

Progressive collapse analyses of high-rise buildings subjected to abnormal loading such as fires, impacts, earthquakes, typhoon, bomb blasts etc. are intended. However it is difficult to perform collapse experiments of the real scale building to determine the capacity of the structure under an extreme loading events. In this study, collapse behavior of a 15 story RC structure building loaded by external explosion pressures were simulated using Extreme Loading Structures (ELS) software. The standoff distance between the RC building and explosives of 1500 kg was 1, 2, 5, 10, and 15 meters. The explosive demolition analysis techniques based on removal of partial support structures following blast scenario was adapted to investigate the transition process of progressive collapse-local damage.

• Journal of the Korea Institute of Building Construction
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• v.20 no.4
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• pp.375-382
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• 2020

Rock drop obstacles on major roads in the border area in South Korea has been installed and operated to prevent and block the movement of enemy units. However, the increase in traffic volume due to the development of the border region causes many problems such as road traffic congestion due to rock drop, traffic safety, and impaired urban aesthetics. Therefore, this study aimed to provide guidelines for demolition and replacement facility installation for rock drop obstacles, which are differently applied to each unit, and to suggest the direction of the Ministry of National Defense's policy regarding maintenance cost for necessary rock drop obstacles required for operation. In this study, as part of a guideline study on the removal of rock drop obstacles and the installation of alternative facilities, a standard unit price was suggested for essential rock drop obstacles, so as to be used as judgment data when deciding whether to remove rock drop obstacles.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.23-25
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• 2011

The purpose of this study is to suggest documentation with determination of concrete then property, according to demolition and restoration the Youngdo bridge which has valuable meaning to modern technique as an only bascule bridge in Korea.

• Explosives and Blasting
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• v.41 no.3
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• pp.62-72
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• 2023

The aging of plant structures due to industrialization in the 1970s has increased the demand for blast demolition. While blasting can reduce exposure to environmental pollution by shortening the demolition period, improper blasting design and construction plans pose significant safety risks. Thus, it is vital to consider optimal blasting demolition conditions and other factors through collapse behavior simulation. This study utilizes a 3-D combined finite-discrete element method (FDEM) code-based 3-D DFPA to simulate the collapse of a chimney structure in a thermal power plant in Seocheon, South Korea. The collapse behavior from the numerical simulation is compared to the actual structure collapse, and the numerical simulation result presents good agreement with the actual building demolition. Additionally, various numerical simulations have been conducted on the chimney models to analyze the impact of the duct size in the pre-weakening area. The no-duct, duct, and double-area duct models were compared in terms of crack pattern and history of Z-axis displacement. The findings show that the elapse-time for demolition decreases as the area of the duct increases, causing collapse to occur quickly by increasing the load-bearing area.

• Journal of architectural history
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• v.22 no.3
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• pp.27-36
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• 2013

The purpose of this study is to analyze the process of lots-subdivision within the block of Gaeksa at Dongnae-bu under the rule of Japanese Imperialism. Gaeksa of the old government office was the sanctuary that symbolized the sovereignty. Therefore it was naturally a main object of demolition and then the site was converted to other purpose. And Gaeksa was not only converted into the elementary school and the public market but the historic site also processed to break down for opening the road through Japanese Occupation of Korea. The main reasons of lots-subdivision were the transfer from state property to private ownership and the urban development project. Needless to say, the particular major reason was derived from the intention of Japanese Imperialism to destroy the traditional urban. As a result, Gaeksa can not be recognized the traces of today and contributes to the demolition of the remaining ancient building. Finally the deformed urban structure was left over from destroyed building.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.107-110
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• 2006

In this study, recently it is urgently required that recycle promotion of construction and demolition waste concrete because urban development is accelerated and redevelopment project is rapidly expanded, production quantity of construction and demolition waste concrete is being increased. On the other hand, it is urgently required that problem solution of demand and supply unbalance of fine aggregate because the sea sand is restricted by exhaustion of river sand and intensification of environment influence evaluation. Therefore, it tries to conform in time necessity, there is the objective of this study to provide the fundamental data about the re-application as the comparison and analysis the quality present condition for the recycled fine aggregate in the inside and outside of the country. At the same time it will be able to improve the quality of the recycled fine aggregate waste as investigating the physical nature and a quality present condition of the recycled fine aggregate from construction waste.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.23-26
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• 2007

In this study, recently it is urgently required that demolition waste concrete has to be recycled on the construction because urban development is accelerated and redevelopment project is rapidly expanded, production quantity of construction and demolition waste concrete is being increased. On the other hand, it has to be solved urgently the unbalance of demand and supply about the fine aggregate because the sea sand is restricted by exhaustion of river sand and intensification of environment influence evaluation. Therefore, the purpose of the study was to show the performance of the apparatus developed by the study and to propose the direction of the optimum operating conditions by having an experimental and positive evaluation about quality of recycled sand produced to develop a separating and selecting device of impurities for recycling of construction wastes which can have a bigger improvement of economical efficiency, productivity, environmental property and quality through a basic property of matter of recycled sand by each operating condition of sand flux in comparison with the existing production system of recycled sand.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.71-86
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• 2016

This paper summarizes the results of a two-year-long research project conducted by the CTBUH on the life cycle assessment (LCA) of tall building structural systems. The research project was made possible thanks to a $300,000 contribution from ArcelorMittal and the support of some of the most important structural engineering firms and players in the tall building industry. The research analyzed all life phases of a tall building's structural system: the extraction and production of its materials, transportation to the site, construction operations, final demolition of the building, and the end-of-life of the materials. The impact of the building structure during the operational phase (i.e., impact on daily energy consumption, maintenance, and suitability to changes) was also investigated, but no significant impacts were identified during this phase.