• 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.

• Explosives and Blasting
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• v.33 no.4
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• pp.14-24
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• 2015

We conducted test blasting in 3 sites to identify the effect on safety of the earth retaining wall by near blasting vibration. As a test result, we confirm that underground structures(earth anchor et al.) are relatively safer than surface structures as the underground vibration is 10~52% of surface vibration at a same distance. We derived surface and underground vibration prediction equations by regression analysis of measured 3 sites' surface and underground vibration PPV. Also we calculated minimum separation distance by blasting pattern about underground and surface curing concrete. Unless any discontinuity which are unsafe on the earth retaining wall appear, blasting work using under 2.4kg per delay is not meaningful to the earth retaining wall's safety as the result of measuring near blasting vibration, confirming change the earth retaining wall's instrument, and observation of structural deformation.

• Explosives and Blasting
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• v.37 no.1
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• pp.1-13
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• 2019

The repeated blasting vibration, which is induced commonly in NATM excavation site, can cause a severe damage to the nearby facilities. It is known that the most effective method for reducing blasting vibration includes the use of electronic detonator, deck charge and change of cut method, and so forth. In order to analyze the effect of blasting vibration reduction, in this study, three-dimensional FDM (Finite Difference Method) program FLAC3D has been used for reflecting the blasting hole, delayed time and charging amount. Also the numerical analysis has been performed by applying a dynamic load to each blasting hole. The cut method has been applied with several methods, such as V-cut and Double-drilled parallel cut, which are common in tunnel construction sites. Also, the field test blasting has been carried out in order to compare the measured data with results of numerical analysis. It was shown that the numerical analysis and the field measurement coincide well.

• 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.27 no.1
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• pp.53-61
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• 2009

R.O.K's explosive manufacturing source was first black powder (B.P) introduced into Korea Dynasty from China. In 1890, black powder was first used for mining blasting in Masan. Nowadays, a vibration control blasting method using the emulsion explosive has been applid to explosive demolition of building structure, subway and road construction sites. In December, 2006, Korean Government and professional society (KSEE) established the blasting guidelines of Modern Vibration Controlled Blasting Method (MVCBM) which is an unprecedented in the world.

• Explosives and Blasting
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• v.23 no.3
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• pp.19-25
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• 2005

Ground vibration, sound pressure and fragmentation size were measured at the construction site using the spall blasting method(SBM). nev were analyzed and compared to those or suggested method by the minister of construction and transportation(MOST). Vibration and sound pressure by SBM were slightly smaller than MOST method but fragmentation size were larger.

• Tunnel and Underground Space
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• v.16 no.4 s.63
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• pp.326-333
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• 2006

In this study, the vibration waveform of the single hole which is not interfered from the different blasting holes is separated, the each dominant frequency which is determinated through the Fast Fourier Transform(FFT) is measured. Also the separation waveform executed a superposition modeling which changes to delay time from 1ms to 80 ms in 1ms interval and controls the number of blasting holes from 2 holes to 15 holes in order to investigate the effect of PPV according to the duration time of the vibration and the number of blasting holes. As a result of analysis, the longer the duration time of the vibration, the longer the delay time which is not interfered from the different blasting holes and the effect regarding the number of blasting holes from inside identical delay time did not appear a lot.

• Explosives and Blasting
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• v.26 no.2
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• pp.92-98
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• 2008

Measuring methods of the blasting vibration were generally divided the. manual method and the automatical method. When using the automatical method, field data of the vibration meter can be transferred to a operation computer by using remote equipments. In this study new automatical system using solar power supply is to be introduced. New automatical system is well suited for the field which is difficult to access and is needed frequent measurements of the blasting vibration. And it can make easy to accumulate the data and control the blasting vibration for safe blasting.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.177-178
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• 2015

Various vibration caused by construction vehicles and equipment movement, rock blasting, and crushing obstacle occurs inevitably in construction sites. In this study, we measured the impact of vibration by blasting rock at construction sites, rock crushing, concrete crushing. The measuring instrument was installed in adjacent buildings and observed that blasting vibration differs depending on the charge weight, blasting distance, and the measuring position. The observation was maintained by allowable peak particle velocity standard according to each standards and references.

• 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.