• Explosives and Blasting
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• v.31 no.2
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• pp.14-24
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• 2013

The most effective way of the rock removing works in the downtown area is to removing rocks by splitting the rock by blasting with small amount of explosives in the hole. However environmental factors not only limit the applications but also increase the forbidden area. As this is a distributed multi-stage blasting method and to reduce vibration by applying the optimized precisioncontrol-blasting method, it is applicable in all situations. The process is to fix the stemming-help plastic sheet to the hole entrance when stemming explosives and insert detonator and explosive primer with same delay time, two or three sets. This method is more efficient in the downtown area where claims and dispute from vibration are expected. This method is easily usable by designing blast pattern even in the area where delay time blasting is difficult after multi-stage explosive stemming due to short length of blast hole (1.2~3.0m) and there is no detonator wire shortage or dead-pressure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.153-173
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• 1993

폭약은 탄광에서 석탄이나 각종 광물을 캐거나, 건설토목현장에서 암반 제거를 위해서 주로 사용되었다. 전쟁에서 군사용으로 파괴를 위한 목적으로 사용되기도 하였으나, 최근의 동서화해 분위기와 남북통일이 무르익는 시대적 조류로 볼때 더이상 파괴용으로의 사용은 제어될 것이고 이제는 평화를 위하여, 건설을 위하여, 산업발전을 위하여 더 많이 사용되어지고 응용되어질 것이다. 작금의 첨단산업의 발달과 산업의 고도화로 우리 화약 업계에도 첨단발파기술의 개발에 많은 관심과 연구.개발을 진행중이다. 첨단발파기술의 응용사례를 소개하면, 건축토목 분야에서 노후 고층빌딩 및 굴뚝의 철거, 노후 교량 및 공장시설의 철거등에 활용되고 있으며, 위락서비스 분야에서 응용으로는 불꽃놀이를 들 수 있다. 최근에는 첨단 과학 장비를 이용하여 각종 꽃불의 모양이 음악과 미술등 예술적인 기능을 기억시킨 컴퓨터를 활용하여 보다 고차원의 공예술품(공학-예술)을 만들어낸다. 아울러 각종 기공식 발파시에도 예술적 기능과 웅장함을 가미하여 그 화려함을 극치에 다다르게 한다. 그외에도 로켓트 발사추진제등의 우주 개발에의 응용, 석유시추등 해양개발에의 응용, 각종 공학 실험연구에의 응용, 폭발 가공에의 응용, 의학에의 응용, 철강산업에의 응용 등으로 그 숫자를 이제는 일일이 나열하기 힘들 정도로 광범위해졌다.

• Explosives and Blasting
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• v.28 no.2
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• pp.69-75
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• 2010

Excavations by blasting in urban area have caused lots of complaints. Hence, special attentions need to be paid to controlling the ground vibrations in designing blasting for those areas. In this study, among the various parameters that can affect the propagation characteristics of ground vibrations, the effect of the priming location of explosive on the ground vibration level was studied for two types of emulsion explosives that had different detonation velocities. Three priming locations of top, middle, and bottom were considered in a charged hole. In the experiment on the effect of detonation velocity, the ground vibration caused by the explosive with a lower detonation velocity showed larger attenuation in the amplitude. The priming locations also affected the ground vibrations levels. The ground vibration level produced from middle priming was found to be larger than the other priming methods under the same blast conditions, but the attenuation of amplitude was also larger in this case. In contrast, the ground vibration level from bottom priming was not larger than the middle priming, but the attenuation was smaller so that the ground vibration was detected at a longer distance.

• Explosives and Blasting
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• v.30 no.1
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• pp.37-51
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• 2012

In this case of "Seongnam~Yeoju double-lanes railroad construction", there were safety facilities which were concerned about damages from vibration and noise. In the project design stage, the rock-splitter method was designed to prevent them. The electronic blasting was considered to improve construction speed and economic value as an alternative tunnelling method, complying with the site's vibration criteria(cowhouse : 0.09cm/sec, residence : 0.2cm/sec). In the environment evaluation report of the eDev, tunnel electronic blasting systems, the blasting pollutions can be managed by the electronic blasting method. The results were successfully conducted with high speed construction without any damages to adjacent facilities.

• Explosives and Blasting
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• v.18 no.2
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• pp.7-13
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• 2000

Abstract The characteristics of bed rock in the study area was classified by means of the crack coefficient estimated from the seismic velocities of in-situ and intact rocks. Various statistical methods were investigated in order to minimize the possible errors in estimating the predictive equation of blasting vibration and to enhance the determination coefficient $R^2$, for more reliable estimation. The determination coefficient showed the highest in the analysis for those groups using weighting function with the number of samples. The analysis for the weighting function employed with standard coefficient and variance also enhanced the determination coefficients significantly compared to the others, but the reliability was slightly lower than results obtained former method. Therefore the most reliable predictive equation of blasting vibration was found to be obtained from a regression analysis of the mean vibration level using the weighting of same distance groups within 15m with the same explosive charge weight per delay. The coefficients, K and n 317.4 and -1.66, respectively, when using the square root scaling, and 209.9 and -1.66, respectively, when using the cube root scaling. The analysis also showed that the square root scaling may be used in the distance less than 31m form the blast source, and the cube root scaling in the distance more than 31m for safe design.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.404-409
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• 2001

현대건설(주)은 중앙선 (덕소 ∼ 양수) 복선 전철공사 실시설계 입찰을 위한 일련의 조사 및 설계를 수행하였다. 본 논문은 사업 구간에 속해 있는 월문터널에 대한 설계를 수행하는 과정에서 현재 기존 노선이 운행되는 있는 단선 터널에 근접한 지역에서 공사 중에 운행되고 있는 열차의 안정성을 확보하기 위한 기초 조사를 선행하였다. 본 논문의 목적은 현재 국내에서 시행되고 있는 근접 터널 시공 문제에서 (특히, 화약 발파에 의한 터널 설계 및 시공) 문제시되고 있는 적절한 진동제어에 대한 수치가 필요 이상으로 적용되고 있다는 점에 대하여 향후, 경제적이고 도전적인 설계를 위한 제시를 하기 위함에 있다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.505-512
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• 1998

지하철과 같은 지하구조물 설계시 기존 구조물 지하를 관통하는 경우가 있다. 본 논문은 기존 역사의 바닥슬래브 밑에 새로운 지하철용 박스 구조물 상부 슬래브가 위치하게 되는 특별한 경우의 굴착 방법을 제시하고 제시된 굴착방법이 상부 구조물에 어떤 영향을 미치는지를 FLAC을 이용하여 검토해 본 것이다. 기존 구조물이 위치하고 있는 지반이 경암인 경우 발파가 주의 깊게 설계되고 시행된다면 발파로 인한 상부 구조의 진동 영향은 충분히 제어할 수 있는 수준으로 예상되었다.

• Explosives and Blasting
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• v.29 no.2
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• pp.81-88
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• 2011

Most of the blast pollution that causes complaints is noise and vibration. Hence, special attentions need to be paid to controlling the underwater noise in designing blasting for those areas. This study estimated underwater sound pressure using distance from blasting and charge per delay and underwater sound pressure level using the underwater sound pressure. To identify the validity of the estimated value, the study demonstrated the results at other areas and compared actual results with estimated results.

• Explosives and Blasting
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• v.26 no.2
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• pp.1-10
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• 2008

The safe level for residential structures has usually been prescribed as just 'particle velocity' in various specifications in Korea. It implies that there is a possibility of interpreting the 'particle velocity' as the PPV (Peak Particle Velocity), PVS (Peak Vector Sum), or something else, depending on the interpreter. As a result, there have always been some difficulties in both designing a controlled blasting and controling the blast-induced ground vibrations. This paper is intended to show what the role of the safe level criteria such as PPV or PVS is, and also how we should use the concept of the scaled distance equation in a controlled blast design. The paper also emphasizes the importance of the allowable level for various residential structures and its uses in each stage of the controlled blast design.

• Explosives and Blasting
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• v.28 no.1
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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.