• 화약ㆍ발파
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• 제17권1호
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• pp.19-26
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• 1999

Rock fragmentation with plasma blasting technique has advantageous properties in contrast to the conventional blasting method in controlling of flying rocks and ground vibrations when residents are complaining or surrounding structures stay in protection from blasting operations. The experiences show in urban construction works that the plasma blasting is the most possible method to prevent damages and minimize adverse environmental impacts. The fragmentation energy level is evaluated by numerical simulation using PFC for various drill hole pattern and tested accordingly to get the feasibility. The energy output of plasma blasting system has been improved to a level of 1 MJ, which can break a $2-3m^3$ granite boulder or 1.5m height bench face. Measurements are carried out to get the ground vibration level and propagation equation. So that the control of the blasting operations can be performed more precisely and safely.

• 화약ㆍ발파
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• 제27권1호
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• pp.47-52
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• 2009

우리나라는 산악지역이 70%이산 분포되어 있는 지형적 특성으로 인하여 굴착작업 시 발파작업은 필수사항으로 되어있으며, 발파작업이 이루어지는 곳에는 발파진동 소음으로 인한 민원이 부수적으로 발생하고 있다. 발파작업을 위해 경제성과 안정성, 시공성에 따라 발파패턴이 선정되어진다. 하지만 민원의 해결을 위한 공법의 무절제한 변경 등이 이루어지고 있는 일들이 발생되는 경우가 빈번하여 이를 방지하기 위해 국토해양부는 설계 및 시공에 대한 표준발파공법을 제시하였다. 그러나 국토해양부표준발파공법(2006년)은 암종에 상관없이 일괄적인 발파패턴으로 설계되어 있으므로 셰일암반 등과 같이 낮은 강도의 암반, 절리가 많이 포함되어 있는 암반에 적용한다고 할 때에 이들 암반의 특성이 고려되지 않은 상태에서 일괄적인 장약량 등의 발파제원에 따라서 경제적인 손실이 생길 수 있다고 생각되어진다. 따라서 이와 같은 셰일 및 응회암반에서 현지암반의 특성을 고려하여 공간격과 저항선의 길이를 조정한 발파제원을 적용하여 시험발파를 수행하여 어느 정도의 경제성 증대 가능성의 결과를 도출하였다. 이를 시작으로 좀더 많은 사례를 통한 정량적 결과를 도출하여 설계 및 시공에 적용한다면 경제성 향상을 기대할 수 있을 것이라 사료되어진다.

• 한국정밀공학회지
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• 제21권6호
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• pp.28-34
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• 2004

The old technique of sandblasting which has been used for decoration of glass surface has recently been developed into a powder blasting technique for brittle materials such as glass, silicon and ceramics, capable of producing micro structures larger than 100${\mu}{\textrm}{m}$. In this study, we introduced oblique powder blasting, and investigated the effect of the impacting angle of particles, the scanning times and the stand-off distance on the surface roughness and the weight-loss rate of samples with no mask, and the wall profile and overetching of samples with different mask pattern in powder blasting of soda-lime glass. The varying parameters were the different impact angles between 50$^{\circ}$ and 90$^{\circ}$, scanning times of nozzle up to 40 and the stand-off distances 70mm and 100mm. The widths of mask pattern were 0.2mm, 0.5mm and 1mm. The powder was alumina sharp particles, WA #600. The mass flow rate of powder during the erosion test was fixed constant at 175g/min and the blasting pressure of powder at 0.2Mpa.

• 화약ㆍ발파
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• 제32권1호
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• pp.10-17
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• 2014

본 연구에서는 중앙아시아에 위치한 카자흐스탄을 방문하여 Kazakhmys광산을 소개하고 국내 발파 기술을 접목할 경우를 가정하여 최적의 발파 설계를 제안하고자 한다. 그 결과, 국내 발파 기술을 사용하더라도 카자흐스탄 광산에서 발생하는 화약 소모량과 천공수 등을 절감하여 최종적인 생산원가를 절감할 수 있는 발파 설계가 가능한 것을 알 수 있었다.

• 화약ㆍ발파
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• 제41권4호
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• pp.41-50
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• 2023

본 연구에서는 굴착 물량 증대와 발파공해 저감을 위해서 전자뇌관을 이용한 수직방향 더블 데크 공법을 적용하였다. 더블 데크 공법은 상부 데크 발파 후 자유면이 완전히 형성되지 않은 상태에서 하부 데크 발파가 진행되면 발파 효율이 감소할 가능성이 있다. 이와 같은 이유로 더블 데크 공법은 데크 단차에 따라서 발파 효율이 달라진다. 따라서 본 연구에서는 홀 단차의 1~5배를 적용한 4가지 데크 단차를 제안하였고, 발파 후 파쇄도 분석을 통해 발파 효율을 평가하였다. 파쇄도 평가 결과 패턴 4(데크 단차=홀 단차×5)의 파쇄도가 가장 좋았으며, 패턴 3(데크 단차=홀 단차×3) 이상에서 파쇄효율이 큰 폭으로 증가하는 것을 확인할 수 있었다. 이에 따라 수직방향 더블 데크 발파 시 데크 단차는 최소 홀 단차의 3배 이상이 되어야 효율적인 발파 효과를 얻을 수 있다고 분석되었다.

• 터널과지하공간
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• 제7권4호
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• pp.267-273
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• 1997

Rock fragmentation with plasma blasting technique has advantageous properties in contrast to the conventional blasting method in controlling of flying rocks and ground vibrations, when residents are complaining or surrounding structures stay in protection from blasting operations. The experiences show in urban construction works that the plasma blasting is the most possible method to prevent damages and minimize adverse environmnetal impacts. The fragmentation energy level is evaluated by numerical simulation using PFC-2D for various drill hole pattern and tested accordingly to get the feasibility. The energy output of plasma blasting system has been improved to a level of 1 MJ, which can break a 2~3 ㎥ granite boulder or 1.5 m height bench face. Measurements are carried out to get the ground vibration level and propagation equation, so that the control of the blasting operations can be performed more precisely and safely.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.681-688
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• 2003

Rock damage induced by blasting can not be avoided during tunnel construction and may affect tunnel stability. But the mutual interaction between tunnel blasting design and tunnel stability design is generally not considered. Therefore this study propose a methodology to take into considration the results of the blasting damage in tunnel stability design. Rock damage is evaluated by dynamic numerical analysis for the most common blasting pattern adopted in road tunnel. Damage zone is determined by using the continuum damage model which is expressed as a function of volumetric strain. And the damage effect is taken into account by the damaged rock stiffness and the damaged failure criteria in tunnel stability assessment. The extend of plastic zone and deformation increase compared to the case of not considering blast-induced rock damage.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.614-621
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• 2004

Blasting is a technique for rock excavation: For instance, a rock cutting in a mountain side to prepare a base for a road. The blasting damage affect the rock slope stability. Therefore control blasting must be used. In this study, cutting cases of Sixty-nine rock blasts were investigated. Blasting damage patterns in rock slope and reinforcement methods are studied.

• 화약ㆍ발파
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• 제8권1호
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• pp.3-16
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• 1990

The cautious blasting works had been used with emulsion explosion electric M/S delay caps. Drill depth was from 3m to 6m with Crawler Drill $\varphi{70mm}$ on the calcalious sand stone(sort-moderate-semi hard Rock). The total numbers of feet blast were 88. Scale distance were induces 15.52-60.32. It was applied to propagation Law in blasting vibration as follows. Propagtion Law in Blasting Vibration $V=K(\frac{D}{W^b})^n$ where V : Peak partical velocity(cm/sec) D : Distance between explosion and recording sites (m) W : Maximum Charge per delay-period of eighit milliseconds or more(Kg) K : Ground transmission constant, empirically determind on th Rocks, Explosive and drilling pattern ets. b : Charge exponents n : Reduced exponents Where the quantity $D/W^b$ is known as the Scale distance. Above equation is worked by the U.S Bureau of Mines to determine peak particle velocity. The propagation Law can be catagrorized in three graups. Cabic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge per delay Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom and over loom distance because the frequency is verified by the distance from blast site. Empirical equation of cautious blasting vibration is as follows. Over 30m----under l00m----- $V=41(D/3\sqrt{W})^{-1.41}$ -----A Over l00m-----$V= 121(D/3\sqrt{W})^{-1.66}$-----B K value on the above equation has to be more specified for furthur understang about the effect of explosives, Rock strength. And Drilling pattern on the vibration levels, it is necessary to carry out more tests.

• 화약ㆍ발파
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• 제9권4호
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• pp.3-12
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• 1991

The cautious blasting works had been used with emulsion explosion electric M /S delay caps. Drill depth was from 3m to 6m with Crawler Drill 70mm on the calcalious sand stone (soft-moderate-semi hard Rock) . The total numbers of feet blast were 88. Scale distance were induces 15.52-60.32. It was applied to Propagation Law in blasting vibration as follows .Propagtion Law in Blasting Vibration V=k(D/W/sup b/)/sup n/ where V : Peak partical velocity(cm/sec) D : Distance between explosion and recording sites(m) W ; Maximum Charge per delay -period of eight milliseconds or more(Kg) K : Ground transmission constant, empirically determind on the Rocks, Explosive and drilling pattern ets. b : Charge exponents n : Reduced exponents Where the quantity D/W/sup b/ is known as the Scale distance. Above equation is worked by the U.S Bureau of Mines to determine peak particle velocity. The propagation Law can be catagrorized in three groups. Cabic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge delay Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom and over loom distance because the frequency is varified by the distance from blast site. Empirical equation of cautious blasting vibration is as follows. Over 30m--under 100m----V=41(D/ W)/sup -1.41/-----A Over l00m---------V=121(D/ W)/sup -1.56/-----B K value on the above equation has to be more specified for furthur understand about the effect of explosives. Rock strength, And Drilling pattern on the vibration levels, it is necessary to carry out more tests.