• Explosives and Blasting
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• v.23 no.2
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• pp.45-56
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• 2005

In this study, fracture formation and fracture volume by blasting demolition of model reinforced concrete pillars were compared with various vertical load and influence of reinforced steel bar. The more vertical load increased, the more tensile cracks and vertical direction cracks produced. In vertical load of 2.0ton, tensile cracks on vertical direction were predominantly produced. Generally, the more vertical load increased, the more bending deformation of concrete steel bar decreased. As a result, vertical load was influenced fracture formation of concrete and bending deformation of reinforced steel bar. Reinforced steel bar was influenced fracture volume of concrete. According to vertical load and influence of reinforce steel bar by blasting demolition of reinforced concrete pillars, drilling and blasting pattern may be modified.

• Explosives and Blasting
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• v.41 no.4
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• pp.41-50
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• 2023

This study, a vertical double-deck method using an electronic detonator was applied to increase excavation volume and reduce blast pollution. In the double deck method, there is a possibility that blasting efficiency may be reduced if bottom deck blasting is carried out without the free surface being completely formed after upper deck blasting. And for this reason, the blasting efficiency of the double deck method varies depending on the deck delay time. Therefore, in this study, we proposed four deck delay times applying 1 to 5 times the hole delay time. And blasting efficiency was evaluated according to fragmentation analysis. As a result of the fragmentation evaluation, the fragmentation of pattern 4 (deck delay time = hole delay time×5) was the best, but it was confirmed that fragmentation efficiency increased significantly from pattern 3 (deck delay time = hole delay time×3). Accordingly, it is analyzed that when blasting a vertical double deck, the deck delay time must be at least three times the hole delay time to obtain an efficient blasting effect.

• Explosives and Blasting
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• v.23 no.2
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• pp.37-44
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• 2005

Recent studies reported that natural block size of rock and joint orientation highly affect on rock fragmentation. In this study, blasting test using high strength cement mortar was carried out to verify this fact. The result of this test indicated that fragmentation is influenced by the joint interval, and at same joint interval condition, fragmentation depends on joint orientation. These results are significantly coincident with field investigations.

• Explosives and Blasting
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• v.42 no.1
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• pp.23-33
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• 2024

Recently, various techniques and patented methods on blasting operation are being newly developed. In this study, test construction of the MDS blasting method was performed, and the fragmentation size and the occurrence rate of rocks exceeding 300mm were measured and analyzed in comparing to normal blasting method. Test construction was performed three times each for normal and the MDS at the same bench for each round, and fragmentation size(P80) and occurrence rate of rocks exceeding 300mm(S30) were measured using digital image processing. A sieve bucket was also manufactured on-site to sort oversized rock particles from muck piles, and their weights and equivalents were measured to calculate actual values. As a result, the fragmentation size decreased of 21.0% with the MDS compared to normal, and 100-S30 decreased of 10.1%, with actual values decreasing of 7.6%. Although there were variations in blasting effects for each round due to differences in rock quality at site, overall, the MDS proved to be more effective compared to normal blasting method under equivalent conditions.

• Proceedings of the KSEE Conference
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• 2004.08a
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• pp.49-75
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• 2004

소음진동 규제법의 강화, 각종 건설민원 발생 및 안전강화 관리 차원에서 현재 국내 터파기 현장 및 각종 토공사에서 종래 시행되어지던 발파공법만으로 시행하는 것은 곤란하다. 건설교통부 설계 지침에서도 진동 규제치의 차이를 두어 파쇄와 발파와의 차이를 확연히 구분하는 실정이다. 기존에 발파는 그 경험이 많아 효과적인 방법 등이 널리 알려져 있지만 파쇄의 경우는 그 시공사례가 많지 않아 그 연구의 필요성이 대두되고 있다. 본 연구는 건교부에서 제시한 암파쇄굴착공법에 사용되어지는 미진동 파쇄기에 대한 연구로써 연암, 보통암, 경암지역에서의 전색제, 적정 패턴, 진동 특성 등을 분석하는데 그 목적이 있다. 시험은 크게 1, 2 타입으로 구분하여 실시하였으며 1타입의 경우는 천공장이 1.5m(180g 장약)이고, 2타입의 경우는 2.5m(360g)이다. 두 패턴을 기본으로 저항선, 공간격을 달리하여 시험을 진행하면서 그에 따르는 진동 및 파쇄정도의 차이를 관찰할 수 있었으며 암석 강도별 예상 진동식을 제안하였다.

• Explosives and Blasting
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• v.19 no.4
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• pp.11-22
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• 2001

토목공사장에서 암파쇄 작업은 경제성과 안정성에 지대한 영향을 미치는 작업이다. 본 논문은 대전지역에서 수행된 암파쇄 공법 설계 및 시공사례로서, 현장암반의 특성을 고려한 적정발파공법을 선정하기 위하여 대상 지역의 지질현황을 조사·분석하고, 또한 민원이 첨예한 도로개설 공사장에서 시험발파를 실시하여 이를 토대로 암절취 공법을 선정하여 시공한 사례보고이다. 대전지역의 지질은 선캠브리아기의 변성암류와 변성퇴적암류 및 이를 관입한 심성암류와 중생대 화강암으로 이루어져 있는 복잡한 분포를 이루고 있다. 사례연구 대상 현장은 편상구조가 현저한 관입 편상화강암 및 화강암질 편마암으로 구성되어 있었으며, 시험발파 및 분석결과를 기초로하여 25.5m이내 지역은 HRS 등 무진동 파쇄공법의 적용을 제안하였고, 25.5∼36m 범위의 대부분 지역은 진동제어를 할 수 있는 제어발파공법을 권장하였고, 기타 진동 영향권에서 비교적 안전한 것으로 나타난 지역은 소발파공법을 적용하도록 제안하였다. 제안된 안에 따라 설계를 보완하고 시공한 결과 문제의 발생없이 성공적으로 시공이 완료되었다.

• Tunnel and Underground Space
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• v.16 no.2 s.61
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• pp.156-165
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• 2006

Already, vari-stem, gas-bag, power deck, air ball etc. are used by various blasting methods to take the advantage of air decking technology in abroad. Air tube product has been used continuously in domestic and air ball product was made recently. In the case study, we analyzed about the application and the effect or air deck blasting method in domestic blasting area. As results or this case study, it was shown that blasting vibration was decreased about $21{\sim}41%$ and quantities or explosives was decreased about $17{\sim}30%$. Also, in the case of using air deck blasting method, fragmentation was shown to be smaller than common blasting method.

• Explosives and Blasting
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• v.35 no.1
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• pp.18-26
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• 2017

In Analysis of Fragmentation of rock blasted, The photo analysis method has been mainly used and these image acquisitions are mainly obtained by digital image from the front of the crushed rock. However, Image analysis is basically advantage of the image of planar shooting not front shooting but There is no way to take a photograph of huge plane rock slope. Thus, Unavoidably It is resolved by distorting or extending the image filmed at the front as well as adjusting it similar to its angle of plane shooting. Lately, With advancing unmanned aerial vehicle, It can simply image the fragment conditions of blasted rock of a high-definition digital image and Through it, It can acquire the most planar image to angle which accumulate cataclastic rock and also can make image analysis. In this study, It has been confirmed that tolerance value of analysis result of image filmed flatly is markedly lower than the existing front filmed image.

• Explosives and Blasting
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• v.21 no.3
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• pp.11-16
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• 2003

다단 장약 터널 진동제어 발파에 대하여 개별요소법과 유한요소해석법으로 수치해석적으로 검증하였다. 그 결과, 단당 장약량을 줄이고 다단으로 분산시키면 발파로 인한 파쇄도 효과적이고, 진동도 감소할 수 있음을 보여 주었다. 이러한 현상에 대하여 파괴역학적으로도 설명하였다.

• Explosives and Blasting
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• v.20 no.3
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• pp.39-48
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• 2002

우리나라는 지질특성상 각종 토공사를 시행할 때 암반 절취가 필수적이다. 그러나 소음진동 규제법의 강화, 각종 건설민원 발생 및 안전관리를 강화하기 위하여 종래에 해오던 일반발파(대발파)공법을 적용할 현장은 거의 없는 실정이므로, 미진동 발파공법과 진동제어 발파공법에 대한 기준품셈 및 시공기술에 대한 연구가 더욱 필요하다. 또한 종래의 미진동 발파공법의 품셈기준으로 되어있는 미진동 파쇄기(CCR, 상품명 Fine Cracker)를 사용한 발파공법은 기존의 암절취에 기술적 문제가 일부 대두되므로 이를 보완하기 위해 퇴적암 절취현장에서 미진동 파쇄기.정밀.에멀젼 화약을 사용하여 비교실험을 하였으며, 최근에 새로운 미진동 파쇄기(상품명 : Fine Cracker Plus)를 개발 시판하게 되어 이를 비교 검토하였다. 그 결과 일축 압축강도 $1623~2060kg/\textrm{cm}^2$의 경암 내지 극경암에서도 양호한 발파효과를 볼 수 있었다.