• 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.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.984-992
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• 2023

Purpose: The core problem of this study is that there are no specific noise regulation standards for domestic blasting work. Currently, the domestic blasting work noise regulation standard has not been established separately, and the noise regulation standard of 80 decibels is corrected by 10 decibels to 70 decibels, which is the daily living noise standard. In contrast, many foreign countries have separate noise regulation standards specifically tailored to blasting work. Accordingly, it is intended to present international reasonable blasting noise standards by comparing domestic and foreign blasting work noise regulation standards. Mmethod: This study can be inferred as a comparative analysis of domestic and foreign noise regulation standards. Data on the current noise regulation standards during domestic blasting and noise regulation standards during blasting operations in the United States, the United Kingdom, Australia, Japan, and China are collected and analyzed. Results: According to the study, the noise regulation value during blasting work at domestic construction sites was not separately established, so it was not properly tailored to the specific and characteristics of blasting noise. In the case of overseas, a realistic noise regulation value was established so that a safer, more efficient and eco-friendly blasting method could be applied to the noise regulation value uniformly during blasting work. Conclusion: In this study, it is hoped that noise regulations will be established during reasonable blasting work, as shown in domestic and international comparative studies, and will be widely adopted without interfering with the introduction of efficient, economical, and eco-friendly blasting methods by complying well with blasting safety standards.

• Explosives and Blasting
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• v.25 no.2
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• pp.11-21
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• 2007

The main structure of Gunsan steam power station was demolished by the toppling method using high explosives. Height of a main building is 58m and a total floor area is $292,000m^2$. It is Rahmen(rigid-frame) structure consisted of almost columns and beams and slabs exist only in one part of the building for the electricity generators equipments. To improve the efficiency of blasting work, it is separated into 4 sectors. Blasting floors were 1, 2, 3, & 4 stories from first sector to third sector, while 1, 2, 5, & 7 of fourth sector were blasted because it had not slabs. About 102.675 kg of the MegaMITE were used with 225 electric detonator and 638 non-electric detonators to check detonator connection and confidence of detonation. The blasting noise and vibration were monitored to evaluate the environment effect and the damage of the nearby structures.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.381-388
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• 2007

The regular RC structures have been transformed into irregular RC structures by alternate load of RC structures during explosive demolition. Numerical simulation programs have contributed to a better understanding of large displacement collapse behavior during explosive demolition, but there remain a number of problems which need to be solved. In this study, the 1/5 scaled 1, 3 and 5 stories RC structures were designed and fabricated. To consider the collapse possibility of upper dead load, fabricated RC structures were demolished by means of felling method. To observe the collapse behavior of the RC structures during felling, displacement of X-direction (or horizontal), displacement of Z-direction (or vertical) md relative displacement angle from respective RC structures were analyzed. Finally explosive demolition on the scaled RC structures using felling method are carried out, collapse behavior by felling method is affected by upper dead load of scaled RC structures. Displacement of X and Z direction increases gradually to respective 67ms and 300ms after blasting. It is confirmed that initial collapse velocity due to alternate load has a higher 3 stories RC structures than 5 stories.

• Explosives and Blasting
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• v.36 no.3
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• pp.19-28
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• 2018

Locally damaged structures caused by earthquake or extraordinary external forces have been required to rapidly be dismantled because of its possibility of additional collapses. Particularly, steel frame structures were demolished by the shaped charge blasting method. Recently a research suggested a shape charge blasting technique which uses bent-shaped charge holder of copper plate and emulsion explosive charge to cut thick steel plates. This study simulated the cutting performance of the bent-shaped charge holder with considering types of explosives, thickness of copper liner and stand-off distances using LS-DYNA software. The shape charge blasting test of a 25mm thickness steel plate were used to calibrate the input parameters of the numerical models. The penetration depth and penetration width were analysed with different types of explosives, thickness of copper liner and stand-off distances.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.87-88
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• 2023

서해안 최고의 동백정해수욕장과 마량리 동백나무숲은 1970년대 오일쇼크 이후 에너지 자립을 위해 발전소를 건설하면서 사라졌다. 그 당시 준공된 화력발전소는 전력공급 이라는 소임을 완수하고 2021년 부터 동백정의 아름다운 옛 모습 그대로 지역주민에게 돌려 주기위한 친환경 사업으로 발전소 철거공사를 시작, 동백정 복원공사를 추진 하기로 했다. 고층 및 중량물의 건축물 및 구조물을 안전하게 해체하기 위해서는 국내 최초 발전소 철골구조물에 대한 발파·전도공법을 채택 하였다. 철거작업은 고위험 공종으로 참여 주체인 발주자, 설계자, 감리자, 시공자 및 근로자 전 계층의 참여로 사전 위험성평가를 통해 근원의 위험요인 발굴 및 안전대책 수립, 수립된 안전대책 100% 이행을 통해 무재해 준공 달성 하기를 기대한다.

• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.57-65
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• 2022

This study simulated the shock wave propagation through the tamping material between explosives and hole wall at blasting works and verified the effect of tamping materials. The Arbitrary Lagrangian-Eulerian(ALE) method was selected to model the mixture of solid (Lagrangian) and fluid (Eulerian). The time series analysis was carried out during blasting process time. Explosives and tamping materials (air or water) were modeled with finite element mesh and the hole wall was assumed as a rigid body that can determine the propagation velocity and shock force hitting the hole wall from starting point (explosives). The numerical simulation results show that the propagation velocity and shock force in case of water were larger than those in case of air. In addition, the real site at blasting work was modeled and simulated. The rock was treated as elasto-plastic material. The results demonstrate that the instantaneous shock force was larger and the demolished block size was smaller in water than in air. On the contrary, the impact in the back side of explosives hole was smaller in water, because considerable amount of shock energy was used to demolish the rock, but the propagation of compression through solid becomes smaller due to the damping effect by rock demolition. Therefore, It can be proven that the water as the tamping media was more profitable than air.