• Explosives and Blasting
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• v.16 no.2
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• pp.34-46
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• 1998

We developed a method to control vibration from some blasting points. This method uses a correlation of vibration waves to decide the most effective delay time to control vibration by interfering vibration waves with each other. We applied this method to the small blasting using mortar blocks and examined the effect on controlling vibration. As the result of the examinations, the maximum vibration velocity by this method caused by five detonators blasting in row of five holes became smaller than that by a detonator blasting in the nearest hole from the measuring point. And the velocity was about one fifth of that of maximum condition in which vibration waves caused by the five detonators arrivved at the same time to the measuring point.

• Explosives and Blasting
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• v.28 no.2
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• pp.50-58
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• 2010

This study explores the slot-drilling method that has not yet enough been studied in Korea and intends to provide a theoretical framework for putting the method into practice in a construction site. The possible reduction of ground vibration by implementing slot-drilling methods is addressed. Two main subjects dealt with include the variation of vibration velocity that is based on the distance between the slot-drilling and the epicenter of blasting and the analysis of appropriate effective dimension of slot-drilling width and height to control blasting vibration. This study shows that effect of vibration reduction decreases when distance of the slot-drilling and the epicenter of blasting is getting larger and also reveals that there is a correlation between the slot size and the vibration velocity at any point.

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

• Proceedings of the Korean Geotechical Society Conference
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• 1993.03a
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• pp.59-62
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• 1993

In this study, various problems of ground vibration from rock blasting have been discussed, and field tests of rock blasting-ground vibration were carried out to find out the system of evaluation and control method for selecting blast design values and the rationale for the selection. Criterla of estimating structural response and damage caused by ground vibration from rock blasting are also discussed for the safety design of blast.

• Journal of the Korean Professional Engineers Association
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• v.15 no.2
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• pp.3-15
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• 1982

The study on prevention measures for vibration and excavation of tunnel for the #3, #4, Seoul Subway. In the Seoul subway tunnel blasting, the drilling pattern and prevention method to seismic vibration are as follows as well as for adaptions of NATM, the supportings of roof and wall holes are arranged with control blasting. 1. The blasting is executed basically using the low velocity explosive such as slurry, Nitrate ammonium explosive, and F-I and F-II explosive for control blasting substituting of existing dynamite. 2. The cut holes are arranged with burn cut pattern and also must be arranged with M/S electrical delay caps substituting of ordinary do]ay caps. 3. Jack leg drills are used in Five Job sites and a jumbo drill in one job site. 4. In performance of safety work and in maintenance of building safety. The drilling length for blasting will not exceed 1.20 meter for round so that the vibration value shall carry below 0.3cm/sec. The harmonizing of better powder, better drilling machine and better technique is only the way of improving tunnelling efficiency and less vibration will help the dereasing of accidence.

• Explosives and Blasting
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• v.36 no.1
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• pp.34-38
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• 2018

It proceed the trial test by applying blasting system with combination of electronic detonator and non-electric detonator(Supex Blasting Method) for the purpose of preventing the over-break as well as controling the blasting vibration and noisy at the site of Boseong-Imseongri railroad section ${\bigcirc}{\bigcirc}$. As a result of that, the blasting vibration and noisy was measured within the allowable standard of vibration. In conclusion, the combination of electronic detonator and non-electric detonator can not only reduce come construction cost, level of vibration and noisy but also get the prevention effect for Public resentment and minimize the rock-damage through over break control.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1471-1478
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• 2013

In this paper, numerical analysis with varying distance and burial depth was performed to recommend the blasting vibration control standard for pre-insulated pipes. The blasting load model applied in the numerical analysis was verified to the comparison with the results of the field tests. It was determined from the results of the numerical analysis that the effective stress either exceeds or approaches the allowable stress of the inner steel pipe for vibration velocity greater than 4.0cm/sec while stability is obtained for vibration velocity below 4.0cm/sec. Therefore, it was determined that the blasting vibration control criteria for pre-insulated pipes must not exceed 4.0cm/sec.

• Explosives and Blasting
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• v.42 no.1
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• pp.1-11
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• 2024

Through existing research and construction cases during tunnel blasting, the electronic blasting method is reported to be more effective in reducing blast vibration than the normal blasting method. However, due to the high price of electronic detonators, they are only used in some blasting sites where security objects are located nearby. Accordingly, this study performed tunnel blasting tests by adjusting the ratio of electronic and non-electronic detonators. And through the research results, the reduction effect of blasting vibration according to the detonator ratio was evaluated. The research results showed that the reduction effect of blast vibration was greatest when 100% electronic detonator was applied. In addition, when more than 52% of the electronic detonator was applied, it was found that the reduction effect was similar to the reduction effect when 100% of the detonator was used.

• Explosives and Blasting
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• v.33 no.1
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• pp.27-34
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• 2015

Recently, the residence complaints have been increased by blast vibration and noise issue due to increased urban blasting works so that the trouble between construction company and residence have been continuously increased. Deck-charge blasting method using electronic detonator provided not only blast vibration and noise control but also minimized residence complaints through shortening of the blasting period. This blasting method will be widely used for maximizing urban blasting productivity.

• Explosives and Blasting
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• v.32 no.3
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• pp.18-25
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• 2014

Ground vibration and noise from blasting operation are known to be the most representative constituents which can cause human and material damage. In this study, the effect of delay time on ground vibration is investigated by adopting seven different delay times in bench blasting. For each delay time, three blasting operations were performed. The prediction equations for blasting vibration are derived from 50 sets of measurement and the time theory of Langefors is evoked in the analysis of the blasting vibrations and frequencies. For the delay times of 8 ms and 28 ms, the average values of ground vibration are 5.76 cm/sec and 5.75 cm/sec, respectively, which are considerably low. Also the cyclic variation in the vibration measurements with the delay time confirms the interference effect. From the application of the measurements of blasting vibration and frequency to the time theory of Langefors, it is concluded that the optimum delay times are 8 ms and 24 ms for the test site.