• Explosives and Blasting
• /
• v.31 no.2
• /
• pp.25-31
• /
• 2013

In this case of "Seongnam~Yeoju double-lanes railroad construction", there were resident houses and gas pipe which were concerned about damages from vibration and noise. Especially, gas pipe which is a diameter of ${\varphi}500mm$ was located under the ground along upside road. The limit of vibration was 1.0cm/sec to protect gas pipe. The electronic blasting systems have been used to control vibration & noise not only gas pipe but also resident houses. The results of tunnelling were successfully conducted with effective vibration control and quick excavation by electronic blasting without any damages to adjacent facilities.

• Tunnel and Underground Space
• /
• v.31 no.3
• /
• pp.198-209
• /
• 2021

Recently, the demand for demolition of unnecessary steel shell structure is increasing due to deterioration and unsatisfactory functional conditions and the issue of demolition is becoming a major highlight. This execution case was intended to describe an application of the felling method, a explosive demolition method to demolish steel shell structures, for the demolition of a steel stack and steel head tank. As a result of the explosive demolition, the steel stack and steel head tank had collapsed precisely according to the estimated direction. And the explosive demolition was completed without causing any damage to surrounding facilities.

• Tunnel and Underground Space
• /
• v.25 no.3
• /
• pp.255-263
• /
• 2015

Explosive blasting is a very useful tool for mining and civil engineering applications. It, however, may cause severe environmental hazards on adjacent structures due to blasting impact. Blast engineers try to make optimum blast design to provide efficient performance and to minimize the environmental impact as well. It requires a pre-assessment of the impacts resulting from the blasting operation in design stage. One of the common procedures is to evaluate the proposed blast pattern through a series of test blasting in the field. Another approach is to evaluate the possible environmental effects using the numerical methods. There are a number of input parameters to be prepared for the numerical analysis. Some of them are well understood, while some are not. This paper presents some results of sensitivity analysis of the basic input parameters in numerical modelling of blasting problems so as to provide sound understanding of the parameters and some guidelines for input preparation.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.4 no.1
• /
• pp.27-35
• /
• 2002

For the excavation of the rock, blast method is put into operation in most of the construction site in Korea. In comparison to other methods of excavation, blast method has many merits such as improvement in efficiency in operation, reducement of operation period, and etc. However, blast operation also creates much loss due to the blast vibration, noise, and fly rocks. Thus, in this study, we have examined main features, rock fragmentation effect and the application of plasma method the one of shallow vibration method. In this study, the attenuation exponent of blast method operated in the site was 1.39~1.40 and that of the plasma method was analysed to be 1.45~2.23. From the location where the distance between excavation location and observation location was over 15 m, most of excavation vibration were measured to be less than 0.2 kine(cm/sec), which is also the allowed standard value of sensitive buildings, such as cultural assets and computer facilities. According to the result of FFT(Fast Fourier Transform) analysis, the frequency measured through blast method in this site was 30~50 Hz and the frequency of plasma method ranges in between 30~130 Hz.

• Journal of the Korean GEO-environmental Society
• /
• v.12 no.2
• /
• pp.5-14
• /
• 2011

The most common problem encountered in domestic tunnel construction sites are solving public resentments caused by damage to adjacent structures and buildings. The most effective excavation method in rock tunnelling is the drilling and blasting, which is the main cause of vibration resulting in the public resentments. In this study, numerical analysis is conducted to compare the vibration reduction effect of line drilling and pre-splitting methods. Furthermore, the numerical simulations are verified and the results are quantified. Finally, various combinations of explosives used in controlled blasting are used and the vibration reduction effects are evaluated, thereby proving the applicability of the controlled blasting for reduction of vibration in tunnelling.

• Tunnel and Underground Space
• /
• v.11 no.1
• /
• pp.14-19
• /
• 2001

The estimation of proper prediction method and the transformation method of environmental regulation standard were carried out by measuring blasting vibration. Vibration velocity was more adequate than vibration level in the blasting design by scaled distance. Thus, design and construction mutt be controlled by vibration velocity, and it is required that the vibration velocity is transformed to vibration level to meet regulation standard. Three transformation methods were studied. First, transformation formula is derived from the shock vibration data only. The second method it the transformation by correlation equation of vibration velocity and vibration level measured at the same time. The last one is the transformation of vibration velocity by FFT. It seems to be difficult to estimate damages by these methods because that every method shows considerable error. But transformation formula of PPV component to vibration level was most practical.

• Explosives and Blasting
• /
• v.24 no.2
• /
• pp.75-82
• /
• 2006

Most of limestone mines in Korea have been developed by a open-cut mining method in consideration of a deposited condition of ore, ore recovery, safety, economic efficiency, etc.. But it has produced environmental problems such as dust flying, blasting noise & vibration, and spoil of farmlands due to slope failure of waste rock mass caused by access road construction, fragmentation & crush of rocks, blasting, transportation, and mineral processing. In this study, it has been suggested for measures to reduce mine hazards caused by open- cut mining of limestone nines.

• Explosives and Blasting
• /
• v.30 no.2
• /
• pp.86-97
• /
• 2012

Ground vibration induced by a bench blasting in the construction site should cause the damage to the structure and indirect damage to a human body, and the vibration level is most practical descriptor for regulating the damage to human body and peak particle velocity is the descriptor for direct damage assesment of the structure. Meantime, the vibration level has not been considered for the blasting design but this study is the case that apply not only peak particle velocity but also vibration level on the blasting design. Also, we strongly believe that this study will be helpful for the management in the blasting site which some civil appeal is concerned. Total 232 measurements of both ppv and vibration level was used to estimate the scale distance. When the regulating threshold was ppv 0.3 cm/s and vibration level 75 decibel, the charge per delay to be estimated with vibration level could be recommended by 1.2~1.4 times than it of ppv. So, it is proven that considering vibration level on the blasting design is reasonable for not only prevention of the civil appeals but also effective blasting. Again, the blasting design which follows the law, "Noise and Vibration Control Act" can actually serve good condition to carry much more economical and effective blasting. The instruments used for this study are the SV-1 model, as first instrument in korea which can measure vibration velocity and vibration level at the same time.

• Journal of the korean veterinary medical association
• /
• v.47 no.9
• /
• pp.852-859
• /
• 2011

최근 우리 축산농가의 주변에서 발생하고 있는 각종 도로 및 우회도로 확장 및 신설, 석산의 채석장, 아파트, 골프장 건설현장 등에서 각종 건설기계의 사용으로 인한 발파, 절토 및 성토부 다짐 공사 등으로부터 나오는 소음 진동 먼지로 인한 가축피해에 따른 분쟁조정신청과 법원의 소송 건수가 부쩍 늘어가고 있는 추세이다. 아직도 가축을 사육하는 농장 주위에 이러한 소음 진동 먼지에 따른 피해를 보는 사례가 있음에도 불구하고, 가축사육농가들이 환경분쟁에 따른 관련 지식과 정보부족으로 인해 실질적인 피해보상근거가 되는 객관적인 자료와 근거제시에 어려움을 겪고 있는 실정에 처해 있다. 이에 필자는 직접 각종 법원소송 사건, 사실조회서 작성과 중앙과 각도 지방환경분쟁조정위원회로 부터 전문가로 위촉을 받아 현지조사를 해 오면서 피해보상에 따른 애로사항과 문제점들을 하나 하나 열거해나가면서 동물병원 개설 임상수의사들에게 구체적이고 실질적인 도움을 드리고 저 본고를 정리하였음을 밝혀두는 바이다.

• Explosives and Blasting
• /
• v.38 no.4
• /
• pp.37-45
• /
• 2020

Todo was an uninhabited island located in the sea of Pusan Newport. It was a small island with the height of 32 m above sea level, and its area including the submerged part was approximately 24,400 ㎡. Unfortunately, the island was located exactly in the middle of the narrow entrance way to the North and South Container Wharfs of Pusan Newport so that a number of ships had to turn quickly to avoid collision with the island, which frequently caused collisions with other ships or cranes. To avoid such a danger and make the water way wider and deeper, the Ministry of Oceans and Fisheries decided to remove the island. This was believed to make even super-large vessels operate safely in the sea of Pusan Newport so that the competitiveness of the port could be highly enhanced. This paper describes in detail the whole process of the removing work, which was the first case of successful underwater blasting operation using bulk emulsion explosives and non-electric detonators to remove a whole island in South Korea.