• Explosives and Blasting
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• v.21 no.3
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• pp.49-60
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• 2003

Nowadays it is tendency to make a remodelling or demolition of old structures with the rapid development of blasting technique. In this treatise it is arranged of improvement procedure of blasting demolition method in korea which was begun since August 1991. Recently, the blasting demolition method has much merits with 60-70% reduction effect of construction period than mechanical demolition method. and so that it has much economical points specially over than 5 storied high buildings. In order to maximalize economical effects of the blasting demolition method, environment safety and recycling, it must be needed. at first to develop the estimating programs against vibration, noise, flying stones, and dust. Also it is required to take a responsibility for using recycling materials after blasting demolition of old structures, and to be invested to advance the blasting demolition techniques.

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.499-506
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• 2018

The number of demolition work is rapidly increasing because the middle- and high-rised buildings constructed over the rapid industrialization and urbanization have been deteriorated in social and structural aspects. However, theoretical approaches or studies related to the demolition cost prediction are still insufficient. Thus, this study derived and analyzed important factors affecting the fluctuation of the building demolition costs. 14 factors was derived through literature reviews and experts' interview, and the importance of each factor was analyzed to the each work(temporary work, structure demolition, and waste disposal) and the entire demolition work by using descriptive analysis. The survey results showed that the demolition costs was greatly influenced by environmental properties of the site. The results of this study can be used as a basis for estimating the approximate cost of the demolition work.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.4
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• pp.153-161
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• 2020

This study investigates the recycling potential of demolition waste (DW) according to building structure, while considering economic aspects. For that, this study surveyed 1,034 residential buildings to collect reliable information on demolition waste generation rates (DWGRs). This study suggested a method for operational cost calculation for each stage and carried out an inventory analysis. The economic value of recycled DW materials was also calculated. And then, the recycling potential(RP) was calculated by building structures and waste types. RP by building structure was low (27-40%), and RP was found in the order of masonry-block, wooden, RC and concrete-brick. By type of DWs, the RP of aggregates was considerably lower than 7%, and DWs such as wood, plastics, and metals showed more than 100% RP. Considering the results of this study, In order to improve the RP of buildings and DWs, the diversification of products that recycled waste like aggregates (i.e., mortar, concrete, bricks, blocks, tiles) and the development of high value-added products are considered to be the most urgent problems. Based on the above RP results, this study proposed a more advanced method for life cycle assessment of buildings and demolition waste.

• Explosives and Blasting
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• v.40 no.4
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• pp.35-46
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• 2022

While the construction of dismantling the old industrial complex and restoring the dismantled industrial site to its original natural environment the is underway. In this paper, we introduce a case of dismantling a turbine building which one of the a large steel frame structures in an old industrial complex by applying the progressive collapse method among the blasting demolition methods. We used a charge container that generates a metal jet to cut dismantling the turbine building. The thickness of the steel structure was adjusted to 30 mm or less by applying gouging, which was a method of digging deep grooves by gas and oxygen flames or arc thermal, in the part where the cutting thickness was thick in the blasting section. The total amount of charge used for the blasting of turbine building was 175 kg, 165 electronic detonators and 124 charge containers. As a result of the blasting demolition, the turbine building was collapsed precisely according to the estimated direction. The blasting demolition was completed without causing any damage to the surrounding facilities.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.97-105
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• 2004

As modern society has been progressed, the demolition method of concrete structure that satisfy the condition of safety, economic efficiency, and environment-friendliness is required. This study investigated problems of existing demolition methods and developed modified method minimizing cooling water and sludge for demolition job. It was also verified the validity of this method based on the finite element methods. A analysis parameters as a number, depth and size of boring, and self weight were introduced for this study, and gave optimal condition for the demolition job and analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.194-195
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• 2021

Due to urban regeneration projects or changes in the living environment, there is an increasing need to demolish old buildings that have lost their functions. Demolition of above ground and underground structures is an important construction project that greatly affects the construction period and safety of the entire process. However, it is difficult for the safety officer to manage the demolition work due to the lack of specific and diverse data applicable to the site of the demolition plan. Therefore, in this study, items that need to be improved in structural safety when the above-ground and underground structures are demolished are reviewed and organized. For the main contents of structural safety management in demolition work, 1) structural review reflecting the order of demolition work, 2) installation and dismantling of steel pipe scaffolding and dust nets, 3) installation and dismantling of system scaffolding, 4) installation and dismantling of fall prevention nets, 5) jack support Installation and dismantling, 6) movement of equipment, movement and planning between floors, 7) equipment for demolition of structures, height of remnants, 8) site cleanup, and 9) equipment operators were categorized and arranged.

• Explosives and Blasting
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• v.31 no.1
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• pp.41-48
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• 2013

Progressive collapse is generally defined as a local failure of structural members occurring due to abnormal load which results in the partial collapse or total collapse of a structure. Unlike progressive collapse, explosive demolition is a method of inducing the total collapse of structure by removing all or portion of structural members. In explosive demolition the partial collapse of the structural members can be controlled at appropriate time intervals by blasting, to induce the progressive collapse of the structure and control the collapse behavior. In this study, a nonlinear dynamic analysis was carried out in order to apply the progressive collapse process to explosive demolition design of the RC structure. The occurrence of progressive collapse of analytical models was examined according to the number of floors, the removed column height and span length. For models that resisted progressive collapse, progressive collapse resisting capacity was evaluated.

• Explosives and Blasting
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• v.31 no.1
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• pp.1-10
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• 2013

In blasting demolition, a method would be chosen among many depends on shape and system of a structure and its surround. To demolish using explosives a structure, which is asymmetric and with high aspect ratio, pre-weakening, explosive locations, detonating delay, and surround conditions are needed to be considered in front to design blasting demolition plan. In this study, to over turn asymmetric and high aspect ratio structure in safe, a simulation using a software named Extreme Loadings for Structures, ELS, had performed. In results, it is achieved optimized pre-weakening shapes and locations, which prevent kick back motion of the structure when it collapse, by analyzing moment distribution caused by pre-weakening. And of structural collapse and by minimizing asymmetric structure's torsional moment. Also, after the demolition, simulation results are also compared with actual collapse behavior. In results, it is confirmed the accuracy of collapse behaviour simulation results, and in blasting demolition, kick back motion can be controled by adjusting pre-weakening shape and location, and the torsional moment of an asymmetric structure also can be solved by optimizing detonation locations and its time intervals.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.797-800
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• 2008

The pre-mixed concrete shotcrete, which can pre-bag the shotcrete materials and thus can save considerable labor activity, will be developed through extensive experiments. The proposed pre-mixed High performance Shooting concrete system included hydro-demolition will be verified though field tests in actual repair and rehabilitation construction sites. This research was on developing of the High performance Shooting concrete by evaluation of site application by field test using new automatic Hydro-demolition and Shotcrete equipment.

• 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.