• Explosives and Blasting
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• 제22권1호
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• pp.15-22
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• 2004

일반적으로 석회석 광산에서의 발파는 ANFO를 사용하여 주로 시행되어지고 있다. Bulk장전 시스템의 도입으로 장약, 발파가 간편하여 효과적으로 발파를 할 수 있고 그 비용도 저렴하다는 장점을 가지고 있다. 그러나 수공에서의 장약이 불가능하고 낮은 위력으로 인해 저항선 및 공간격의 제한이 커서 이에 따르는 발파효율의 저하가 불가피 하였다. 본 연구는 현재 해외에서 일반화되어 사용되고 있는 Bulk EMX(HiMEX)폭약을 국내 현장에 적용함으로 그 적용 방법과 이점을 규명하고자 시행되었다. 대규모 석회석 광산을 대상으로 적정 패턴을 산출하기 위해 기존의 발파 패턴과 비교하여 시험발파를 시행하여 저항선 및 공간격을 산정 하였으며 이를 토대로 해서 성신양회, 현대시멘트 영월사업소와 함께 장기간 시험발파를 실시하고 그 자료를 검증하였다. 그 결과 HiMEX는 초유폭약에 비해 비중이 높아 공당 장약량은 45%정도 증가하나, 1발파 당 생산 물량이 증가하여 5%이상의 장약량 감소효과를 볼 수 있었다. 또한 35∼50%정도의 천공비용이 감소되는 것으로 나타났다.

• Explosives and Blasting
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• 제23권1호
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• pp.19-30
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• 2005

In this study, the standard particle velocity equations and the equation for calculating specific charge weight with application of rock fracture method using the finecker plus are suggested and the existing equation of fragmentation was transformed into one applicable to finecker plus. Standard rock fracture pattern was designed. Square root scaled equation is $V=345.39(D/\sqrt{W})^{-1.4484$. computable equation to specific charge wei인t is $W_f=(2.3\~2.5)\;f_agdV$, charge weight per hole is 0.54kg, and proportion of diameter 30cm fragmentation is about $48.7\%$. This rock fracture method nay him out to be more excellent than the other methods.

• Explosives and Blasting
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• 제37권1호
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• pp.24-33
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• 2019

Recently, Electronic Detonators have gradually increased their performance for various purposes such as vibration control and improved Fragmentation. This study analyzed the vibration estimation equations of electric and electronic detonator blast by comprehensive analysis of the vibration data collected during electric and electronic detonator blast waves at the comparison sites of urban areas, geology and soil conditions, stone quarries and mines in different areas of Korea from June 2017 to December 2018. It has been confirmed that electronic detonator blast can meet the criteria for allowing vibration even if maximum charge weight per delay is increased by 1.5 times compared to the electric detonator blast.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 한국암반공학회 2001년도 춘계학술발표회 논문집
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• pp.63-74
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• 2001

실린더 컷은 터널 굴착단면의 크기에 관계없이 널리 이용된다. 본 연구에서는 발파당 굴진장을 증대시키기 위하여 종래의 방법과 다른 새로운 방법을 제안하였다. 이 방법의 새로운 패턴은 그림과 같으며, 각 단계별로 상세한 저항선, 공간간격은 별도 그림과 같다. 새로운 실린더 컷 방법과 종래의 방법과의 결과는 다음과 같다. 종래 방법은 굴진장이 천공장의 90-95%인데 비하여 새로운 방법은 대체로 99.5%이다. 비장약량이 1.363kg/㎥에서 1.297로 약 5% 감소되며, 비천공장이 2.393m/㎥에서 2.130으로 약 8% 감소된다. 그밖에 지반진동, 비산, 파쇄암의 크기 등이 종래 방법에 비하여 우수함을 확인하였다.

• Tunnel and Underground Space
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• 제11권3호
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• pp.248-256
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• 2001

The cylindrical cut is most frequently used in tunnel blast regardless of their dimensions. In this study the new parallel cut is proposed to raise advance per round, which is considered to be an elevation of the traditional cylinder cuts. The general geometric pattern of a new cut with parallel blast holes is proposed. The detailed burden and spacing between the central blasthole and those of the four section are also given. The blast results between new cut and traditional cylinder cut are given. The main results of this study are as follows. 1) The average advances per rounds in new cuts can reach 99.5% of drilling length. That of traditional cylinder cuts are known approximately 90∼95% 2) Specific charge weight of new cut compare to that of cylinder cut is approximately reduced 5% from 1.363 to 1.297 kg/㎥ 3) Specific drilling rate is also reduced 8% from 2.393 to 2.130 m/㎥ 4) Vibrations, fly rock, and fragmentation produced by the new blast are to be proved superior to those of the traditional cylinder cuts.

• Explosives and Blasting
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• 제28권1호
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• pp.27-39
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• 2010

Blast design equations based on the concept of scaled distances can be obtained from the statistical analysis on measured peak particle velocity data of ground vibrations. These equations represents the minimum scale distance of various recommendations for safe blasting. Two types of scaled distance widely used in Korea are the square root scaled distance (SRSD) and cube root scaled distance (CRSD). Thus, the design equations have the forms of $D/\sqrt{W}{\geq}30m/kg^{1/2}$ and $D/\sqrt[3]{W}{\geq}60m/kg^{1/3}$ in the cases of SRSD and CRSD, respectively. With these equations and known distance, we can calculate the maximum charge weight per delay that can assure the safety of nearby structures against ground vibrations. The maximum charge weights per delay, however, are in the orders of $W=O(D^2)$ and $W=O(D^3)$ for SRSD and CRSD, respectively. So, compared with SRSD, the maximum charge for CRSD increases without bound especially after the intersection point of these two charge functions despite of the similar goodness of fits. To prevent structural damage that may be caused by the excessive charge in the case of CRSD, we suggest that CRSD be used within a specified distance slightly beyond the intersection point. The exact limit is up to the point, beyond which the charge difference of SRSD and CRSD begins to exceed the maximum difference between the two within the intersection point.

• Explosives and Blasting
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• 제31권2호
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• pp.1-5
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• 2013

Parameters of Swedish bench blast design was analyzed by robust design method. Orthogonal array which is adopted in this study was $L_9(3^4)$ and the parameters were hole diameter, explosive type, hole inclination and rock factor of 3 levels. Result of analysis showed that maximum and minimum burden are most affected by hole diameter, followed by explosive type, rock type and inclination of hole. Parameters affecting specific charge are in the order of rock type, explosive type and to specific drilling are hole diameter and explosive type. Cost analysis showed that robust design is capable of parameter optimization.

• Explosives and Blasting
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• 제19권1호
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• pp.31-40
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• 2001

일반적으로 장공발파(長孔發破) 방법(Long hole blasting method)은 그동안 주로 대규모 채탄막장이나 댐 기초굴착, 광산 등에서 행하여져 왔으나 최근 토목터널에서 시공 효율성 및 경제성을 목적으로 관심이 높아지고 있다. 기존의 터널설계 패턴은 I -Type을 기준으로 3.5~3.8m 천공이며 신공법 적용시 최대 4.Om까지 설계되는 것이 보통이었다. 과거 착암장비는 천공장이 늘어남으로서 슬러지에 의한 천공속도가 저하되어 천공비가 증가하기 때문에 빠른 슬러지 배제가 필요하고 Rod의 휨 현상에 의한 천공오차의 증대를 초래할 수 있는 단점이 있었다. 그러나 최근 장비의 발달로 인하여 천공각도 및 천공장 등을 Computer로 모니터링하여 제어할 수 있어 정밀한 천공이 가능하여 졌고 또한, 고성능 에멀젼계 폭약(Super Emulsion)의 개발로 그동안 극 경암터널에서 에멀젼계 폭약의 단점으로 여겨졌던 비 장약량의 증대와 사압현상의 발생, 굴진효율 저하문제론 극복할 수 있었다. 따라서 본 연구는 현재 건설중인 대상현장을 중심으로 장공 터널발파의 효율성과 경제성을 분석하고 나아가 암질에 따른 새로운 Type별 설계기준을 마련하는 기초자료로서 활용하고자 하였다. 된 연구의 대상현장은 충북 괴산군 영풍면 소재 중부내륙(여주-구미간) 고속도로 제 9공구 이화터널 건설공사현장으로 $\varphi{102mm}$ 무 장약공 Cylinder 4공을 이용한 심발법을 사용하였으며 천공장은 최대 5.0m로 2000년 11일 15일에서 동년 12월 15일까지 31일간 총 112회의 시험발파를 실시하여 평균 92%의 높은 굴진 효율을 기록하였다.

• Explosives and Blasting
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• 제9권1호
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• pp.3-13
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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 ${\phi}70mm$ on the calcalious sand stone (soft -modelate -semi hard Rock). The total numbers of test blast were 88. Scale distance were induced 15.52-60.32. It was applied to propagation Law in blasting vibration as follows. Propagtion Law in Blasting Vibration $V=K(\frac{D}{W^b})^n$ were 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 $\frac{D}{W^b}$ 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 catagorized in three groups. Cubic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge Per delay Plots of peak particle velocity versus distoance were made on log-log coordinates. The data are grouped by test and P.P.V. The linear grouping of the data permits their representation by an equation of the form ; $V=K(\frac{D}{W^{\frac{1}{3}})^{-n}$ The value of K(41 or 124) and n(1.41 or 1.66) were determined for each set of data by the method of least squores. Statistical tests showed that a common slope, n, could be used for all data of a given components. Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom 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 ${\cdots\cdots\cdots}{\;}41(D/sqrt[2]{W})^{-1.41}{\;}{\cdots\cdots\cdots\cdots\cdots}{\;}A$ Over 100m ${\cdots\cdots\cdots\cdots\cdots}{\;}121(D/sqrt[3]{W})^{-1.66}{\;}{\cdots\cdots\cdots\cdots\cdots}{\;}B$ where ; V is peak particle velocity In cm / sec D is distance in m and W, maximLlm charge weight per day in kg K value on the above equation has to be more specified for further understaring about the effect of explosives, Rock strength. And Drilling pattern on the vibration levels, it is necessary to carry out more tests.

• Journal of Industrial Technology
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• 제26권A호
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• pp.17-28
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• 2006

In underground drilling and blasting, particularly in small headings(generally under $20m^2$), the prospects for changes of blast parameters are usually more limited than those employed by large area tunnel(over $20m^2$). It is also well known that the consumption of explosives and specific drilling rate for small tunnel areas are exponentially increased also tunnel areas decrease. To confirm above results, some tests for two tunnels(irrigation water tunnel with $6.0m^2$ area, electric supplies tunnel with $15.0m^2$) are also carried out in this study. As a results, specific drilling rate and specific charge for irrigation water tunnel were decreased from 13.8 to $7.7m/m^3$ and from 4.88 to $2.56kg/m^3$ respectively. Those for electric supplies tunnel were also decreased from 8.0 to $4.9m/m^3$ and from 3.46 to $2.22kg/m^3$.