• Explosives and Blasting
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• v.16 no.3
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• pp.35-48
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• 1998

An overview of the plasma rock fragmentation system, the first commercial application of plasma blasting, is presented. Plasma blasting is based on the fast delivery of stored electrical energy to fracture the rock. The capacitor bank, switching device, cable and blasting electrode employed in the system are described. Utilization of the chemical energy delivered from the electrolyte and the development of a large charge transfer switch using pseudospark enabled the commerciailzaion. The vibration and noise level of the blasting is acceptable in the most ground breaking.

• Explosives and Blasting
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• v.17 no.2
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• pp.19-35
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• 1999

Rock fragmentation with plasma blasting technique has advantageous properties in contrast to the conventional blasting method 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 patterns 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 1.5m height bench face. Measurements are carried out to get the ground vibration level and propagation equation, so that control of the blasting operations can be performed more precisely and safely.

• Explosives and Blasting
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• v.17 no.1
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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.

• Explosives and Blasting
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• v.23 no.3
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• pp.57-74
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• 2005

In the past, explosives like dynamite was used to blast rock. However, today it is difficult to use explosives in urban blastinglike excavation for subway, building, and housing land. According to Korea Department of Construction and Transportation's proposal for blasting design manual and test blasting, from TYPE I blasting to TYPE IV blasting are recommended when we determine 0.3cm/sec(centisec) as a maximum allowable ground vibration with a distance between $25m\~120m$ from structures. This article was written to introduce one of TYPE I (reck blasting within 25m from structures) blasting method, Nano-Plasma blasting method. When Nano-Plasma blasting method is applied in urban blasting job, ground vibration (15m away from blasting point) is expected 0.1cm/sec, which is only half of a ground vibration when low ground vibration blasting method is applied. By this unique characteristic, Nano-Plasma blasting method is epochal urban blasting technique.

• Tunnel and Underground Space
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• v.7 no.4
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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.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.129-136
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• 2001

Blasting method is used most engineering works for rock excavation. Blasting method is done much to upgrade of operation efficiency, contraction of construction period than other method. But blasting method happens damage by blasting vibration, nose and scattering. Therefore this study examined about effect, characteristic and application of Plasma method. To confirm effect measured vibration, noise and frequency, and analyzed data compare with general blasting.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.557-575
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• 2020

Plasma blasting which is generated by high voltage arc discharge of electricity is applied to soil mass to improve permeability of soil and cleaning efficiency of oil contamination. A new high voltage generator was manufactured and three types of soil including silty sand, silty sand mixed with lime and silty sand mixed with cement were prepared. Small and large soil columns were produced using these types of soil and plasma blasting was performed within soil columns to investigate the variation of soil volume penetrated by fluid and permeability. Soil volume penetrated by fluid increased by 11~71% when plasma blasting was applied in soil. Although plasma blasting with low electricity voltage induced horizontal fracture and fluid penetrated along this weak plane, plasma blasting with high voltage induced spherical penetration of fluid. Plasma blasting increased the permeability of soil. Permeabilty of soils mixed with lime and cement increased by 450~1,052% with plasma blasting. Permeability of soil increased as discharge voltage increased when plasma blasing was applied once. However, several blastings with the same discharge voltage increase or decrease permeability of soil. Oil contaminated soil was prepared by adding diesel into soil artificially and plasma blasting was performed in these oil contaminated soil. Cleaning efficiency increased by average of 393% for soil located nearby the blasting and by average of 239% for soil located far from the blasting. Cleaning efficiency did not show any correlation with discharge voltage. All these results indicated that plasma blasting might be used for in-situ cleaning of oil contaminated soil because plasma blasting increased permeability of soil and cleaning efficiency.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.433-445
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• 2021

Plasma blasting by high voltage arc discharge were performed in laboratory-scale soil samples to investigate the fluid penetration efficiency. A plasma blasting device with a large-capacity capacitor and columnar soil samples with a diameter of 80 cm and a height of 60 cm were prepared. Columnar soil samples consist of seven A-samples mixed with sand and silt by ratio of 7:3 and three B-samples by ratio of 9:1. When fluid was injected into A-sample by pressure without plasma blasting, fluid penetrated into soil only near around the borehole, and penetration area ratio was less than 5%. Fluid was injected by plasma blasting with three different discharge energies of 1 kJ, 4 kJ and 9 kJ. When plasma blasting was performed once in the A-samples, penetration area ratios of the fluid were 16-25%. Penetration area ratios were 30-48% when blastings were executed five times consecutively. The largest penetration area by plasma blasting was 9.6 times larger than that by fluid injection by pressure. This indicates that the higher discharge energy of plasma blasting and the more numbers of blasting are, the larger are fluid penetration areas. When five consecutive plasma blasting were carried out in B-sample, fluid penetration area ratios were 33-59%. Penetration areas into B-samples were 1.1-1.4 times larger than those in A-samples when test conditions were the same, indicating that the higher permeability of soil is, the larger is fluid penetration area. The fluid penetration radius was calculated to figure out fluid penetration volume. When the fluid was injected by pressure, the penetration radius was 9 cm. Whereas, the penetration radius was 27-30 cm when blasting were performed 5 times with energy of 9 kJ. The radius increased up to 333% by plasma blasting. All these results indicate that cleaning agent penetrates further and remediation efficiency of contaminated soil will be improved if plasma blasting technology is applied to in situ cleaning of contaminated soil with low permeability.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.535-542
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• 2010

Various difficulties have been increased in the construction of public structure; like the road in the overcrowding urban area, because of civil complaint, cost and period of construction. In oder to overcome these social problems, the tunnel has been planned the road design. Despite the resolution, there are many technical problems when constructed near facilities. The design of new tunnel below the existing service reservoir is applied to the ambient vibration blasting using Plasma. The result of test blasting was exceeded the standard ("2kine"). So it was considered a countermeasure for the vibration reduction applied to change the controlled blasting method, reduce the charge, add the pre middle horizontal hole in the cut blasting site, and so on. The result was satisfied the standard. Accordingly, if the quality of blasting process can be managed well, the application of this alternative method is highly effective one. Also, based on cost analysis between two methods, the alternative method is very competitive.

• Explosives and Blasting
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• v.30 no.2
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• pp.59-65
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• 2012

This study improved constructability and cost efficiency that are disadvantages of existing a mechanical excavation & similar blasting methods(plasma, gel, etc) and introduced cases of development and practical applications of Low vibration explosives(LoVEX) that minimizes blast vibration. The low vibration explosives(LoVEX) is suitable to Type-1 in standard blasting patterns of Ministry of Land, Transport and Maritime Affairs(MLTM) and delay blasting is possible. Moreover, the low vibration explosives improve construction and work efficiency while the level of vibration is reduced to about 60~70% of normal emulsion explosives. Additionally, this study suggested standard blasting patterns, the prediction equation of blasting vibration, and construction methods.