• Journal of Environmental Science International
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• v.18 no.1
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• pp.41-47
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• 2009

In building demolition work, major dust-generating activities are blasting concrete and rock. The aim of this study was to find the characteristic of particle size of dusts which were generated during building demolition work using explosion. The DustMate of the Turnkey-Instruments Ltd. was used for particulate size-selective sampling of the four sites. TSP(Total Suspended Particle), PM10(Particle Matter $10{\mu}m$), PM2.5(Particle Matter $2.5{\mu}m$), and PM1.0(Particle Matter $1.0{\mu}m$) were measured during building demolition work using explosion. The large particulate (higher than the diameter $10{\mu}m$) showed to be higher than 50%. The particulate ranged from $10{\mu}m\;to\;2.5{\mu}m$ showed about 30-40%. PM2.5 was not scarcely detected in the samples collected for building demolition work using explosion. We conclude that the dust generated during building demolition work using explosion has not most respirable particulate.

• Explosives and Blasting
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• v.11 no.4
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• pp.9-27
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• 1993

This paper is on the current and prospect of the most advanced explosive technics, Futhermore, utmost needed and centered interesting basic theory, The demolition is described with counter plan on the problems of carrying out example. Specified description noted on the pollution especially noisy, vibration, dust and disperse pollution with comprehensive counter plan. Although it has some insufficiency, 1 expect my paper will be to advance the explosive technics.

• 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.

• Explosives and Blasting
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• v.24 no.2
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• pp.75-82
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• 2006

Most of limestone mines in Korea have been developed by a open-cut mining method in consideration of a deposited condition of ore, ore recovery, safety, economic efficiency, etc.. But it has produced environmental problems such as dust flying, blasting noise & vibration, and spoil of farmlands due to slope failure of waste rock mass caused by access road construction, fragmentation & crush of rocks, blasting, transportation, and mineral processing. In this study, it has been suggested for measures to reduce mine hazards caused by open- cut mining of limestone nines.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.126-129
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• 2007

In order to ruduce traffic-jam, it is requested to extend road. As a result, the construction of tunnels is inevitable considering our mountatinous topography. In tunnel construction work, major contamination materials occur from rock drilling, blasting rock, rock transporting, and short-creat. After rock blasting, a very high concentration of particles over $5000{\mu}g/m^3$ is maintained for 4 h when air is supplied by pans, by which the construction work has to be delayed at least 30 min. Although dry dust collectors are used, the effective operation time span is limited to 3 h. In this work, the behavior of particles in air and use of particle removal instruments are investigated. As a result, it was important to compare efficiencies of dry and hydro dust collectors.

• Tunnel and Underground Space
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• v.25 no.1
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• pp.46-55
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• 2015

A water tube with detonating cord was devised to control the blast dust. Water diffusion experiments with different detonating cord positions were conducted during the series of experiments to optimize the design parameters of the tube. Images from high speed camera were analyzed to evaluate the results. AUTODYN program was adopted to simulate the diffusion process of water and compared with the images. Diffusion of water shows cross flow in case of external charge while the internal case shows radial flow. A bubble ring was formed during the numerical analysis of internal charge case as occurred in underwater blast. An additional bubble ring was formed by the reflection pressure from the ground. And the Weber number was determined as sufficient for spray atomization performance of the water tube.

• 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.39 no.3
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• pp.15-23
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• 2021

Ventilation shafts are pathways in mines and tunnels for the removal of dust or smoke during underground space construction and operation. In mines, blasting with long blast holes is preferred for the excavation of a ventilation shaft in the 10~20m long crown pillar section. In this case, the bottom part of the blast hole is completely drilled in order to determine the drilling error, and this causes a problem of lowering the explosive charge and blasting efficiency. It is possible to solve the problem of explosive loading and to increase the blast efficiency by covering the curb of the blasthole by using stemming material. In this study, simulations for the blasting of a ventilation shaft were performed with various stemming lengths and the blasthole diameters(45, 76mm) using AUTODYN 2D SPH(Smooth particle hydrodynamics) analysis technique. Also the optimal bottom stemming column was derived by checking the size of the boulder and burden line according to blasting. Analysis result, blasting efficiency is lessened in case of stemming length less than 30cm and the optimal length of the stemming material should be 30cm or higher to achieve high efficiency of blasting.

• Explosives and Blasting
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• v.13 no.4
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• pp.73-81
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• 1995

Explosives demolition mothod is allowed for more efficient time-saving and safer demolitioni operations as compared to conventional / mechanical demolition methods. CDI has to minimize the effects of noise, dust and various demolition hazards to the public areas, and residences that are located adjacent to the project site. CDI's explosives demolition work on the Nam san Foreigner's Apartment Complex and chosun trading Co's factory are backed by over 45 years of explosives experience in the demolition of over 6,000 structures worldwide, many of these structures are similar to the Nam san Foreigner's Apt. and Chosun trading's factory in construction and proximity to sensitive adjacent exposures. Recoginized worldwide as the founder of the leader in explosives demolitioni technology, CDI always will applied "State-of-the-Art" explosives techniques to safely and successfully achieve the desired demolition results on these project. CDI has never injured, much less caused any fatality, to either a worker on one of our sites or to a third party during the implosion of high-rise structure.

• Journal of Drive and Control
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• v.17 no.4
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• pp.15-22
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• 2020

With the need for efficient maintenance technology to reduce maintenance costs for steel bridges, repainting robots are being developed to automate the work in narrow and poor bridge spaces. The repainting robot is equipped with a blasting module to remove paint layers and contaminants. This study developed a prototype monitoring module to be mounted on the repainting robot. The monitoring module analyzes the condition of the painting surface through a camera installed in the front, guides the direction of movement of the robot, and provides the operator with a video to check the working status after blasting through a camera installed in the back. Various image visibility enhancement technologies were applied to the monitoring module to overcome worksite challenges where incomplete lighting and dust occurs.