• Tunnel and Underground Space
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• v.14 no.2
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• pp.108-120
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• 2004

Dynamic analysis has been increased recently to analyze the effect of the blasting vibration on the rock mass as well as the surrounding structures. The major input parameter far the general dynamic analysis, however, is merely the blasting pressure which can be obtained from the blasting pressure-time history curves. But in case of the complicate geological condition it is not simple to apply the blasting pressure on the numerical analysis because e ground vibration characteristics should be obtained considering the complexity of ground condition. Therefore the authors tried to use the blasting vibration waveform as an input data This vinylation frequency could be obtained from the test blasting in the Pasir mine, Indonesia. Through the dynamic numerical analysis on the slopes in Pasir, the current situation of this slope could be simulated precisely.

• Tunnel and Underground Space
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• v.2 no.2
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• pp.199-211
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• 1992

Blasting vibrations of 3 quarries and 5 construction sites were measured and investigated with two reference data. Square and cubic root scaled distance were similar in fitness to peak particle velocity of individual blasting site, but the former is better fitted in total. It was suggested that the limit scaled distance for domestic surface blasting be 40kg/$\textrm{cm}^2$ for 10mm/s level and 60kg/$\textrm{cm}^2$ for 5mm/s level, which were lower than the OSM's regulation. Prevailing vibration components were in the order of radial, vertical and transverse directions. Prevailing vibration components were in the order of radial, vertical and transverse directons. Site factors K and m were 242 and -1.283 for all studied area, 357 and -1.348 for construction sites, 118 and -1.160 for quarries. Most prevailing frequency was in the range of 10~2Hz. Overlapping effect of delayed blasting vibrations were insignificant. Vibration history of delayed blasting was longer than simultaneous blasting, and it became longer as measuring distance increased. Wave form and predominant frequencies were more complicated for delayed blasting than instantaneous blasting. The influence of blasting scale and measuring distance were not significant to determine peak particle velocity equation.

• Tunnel and Underground Space
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• v.17 no.6
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• pp.484-492
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• 2007

The blasting vibration prediction in the country is mainly carried out by using the scaled distance method. But, this method needs a real-scale test blasting. The blasting vibration prediction has been performed using the data measured at borehole blasting for the purpose of a geological investigation before beginning a construction of a tunnel. In this prediction method, it is difficult to reflect the propagation characteristics of ground vibration generated from a real-scale blasting. propagation. This paper presents a new method for estimating blasting vibration by using superposed data of single hole blasting waveform with a delay time.

• Tunnel and Underground Space
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• v.9 no.1
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• pp.12-19
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• 1999

In this study, ground vibrations of a surface blasting for golf links and a tunnel blasting for highway construction were measured to investigate the effect of blasting conditions such as total charge and distance from blasting point. In surface blasting, site factor K and n were 74.1 and -1.37, respectively, which were analyzed by means of cube root scaled distance. The more were measuring distance, the higher were absolute value of K and n. Principal frequency was in range of 5~60 Hz in surface blasting, where that of 80 percent was in range of 10~30 Hz. On the other hand it was in range of 25~98 Hz in tunnel blasting, which showed higher than of surface blasting.

• Journal of Korean Tunnelling and Underground Space Association
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• v.3 no.1
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• pp.21-26
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• 2001

Till now a lot of studies has been performed to increase the efficiency of tunnel blasting. Nevertheless there are still uncertainties of input parameter to determine the specific charge. In order to solve this problem, the rock types and the charges of 17 road tunnel sites were analyzed. As a result of these analyses an empirical formula depending on rock type and charge was developed. Through this formula rational tunnel blasting will be designed by quantitative method rather than by assumption.

• Explosives and Blasting
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• v.37 no.3
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• pp.25-33
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• 2019

Controlling the blast-induced damage zone(BDZ) in mining excavation is a significant issue for the safety of employees and the maintenance of facilities. Numerous studies have been conducted to accurately predict the BDZ in underground mining. This study employed the dynamic fracture process analysis (DFPA) to estimate the BDZ from a single hole blasting. The estimated BDZ were compared with the results obtained by Swedish empirical equation. The DFPA was also used to investigate the control mechanism of BDZ and fracture plane formation around perimeter holes for underground mining blasting.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.2
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• pp.185-191
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• 2008

Today, Large and bigger underground construction are increased. In this study, Blating used electronic detonation (OBM Method) and non-electric detonation are carried out. Through comparison with two method, reduction of vibration and noise and efficiency of construction are investigated. As a result of this study, using electronic detonation is shown that it can control lower vibration and noise level, and better HCF, mucfile, advance rate and fragmentation.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.520-533
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• 2021

It is necessary to increase the blasting efficiency in order to minimize the economic loss caused when the excavation cross section is reduced due to the stability problem of underground mining development, and for this, a new blasting design is proposed. In this study, the blasting efficiency of the general design in the field, the suggestion designI, which added two columns to production blasting, and the suggestion design II, which added one column to create asymmetry, is compared. Advance rate and fragmentation were selected as the evaluation index of the blasting efficiency. In the case of advance rate, compared to the normal, the suggestionI improved by 6.07% and the suggestionII improved by 4.65%. In the case of fragmentation, based on P80, compared to the normal, the suggestionI reduced about 58% and the suggestionII was about 47%. Accoording to the evaluation index, the suggestion designI shows better blasting efficiency than the suggestion designII. But considering the additional work time and cost required for the suggestion designI due to the insignificant difference in the evaluation index results, the asymmetry V-cut, the suggestion designII, is judged to be a more suitable blasting design for the site.

• Tunnel and Underground Space
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• v.26 no.5
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• pp.348-362
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• 2016

This study describes the results of blasting overbreak analysis using the stereo photogrammetry method in an underground mine. For comparing its quantitative measurements, LIDAR system was applied to the test site and blasting overbreak was analyzed for 4 test blasting operations. The difference in values obtained from the two methods showed only 0.81% in volume and 1.05% in area, respectively, therefore authors verify the field applicability of stereo photogrammetry method on underground mine. The volumes of overbreak measured from 4 test blastings were $29.84m^3$, $22.45m^3$, $14.54m^3$ and $5.46m^3$, respectively, in photogrammetry analysis on excavation surface, and it was shown that the volume of overbreak decreases with blasting sequence. From these measurements, it is concluded that the stereo photogrammetry method can describe the underground excavation surface effectively and the its quantitative data can be used for analysis of volume, area and overbreak of excavation zone.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.4
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• pp.285-303
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• 2023

Interest in building underground spaces is increasing for the creation of downtown infrastructure and efficient space utilization. A representative method of utilizing underground space is a tunnel, and in addition to road tunnels, the construction of utility tunnels such as power conduits and utility conduits is gradually increasing. The current basic tunnel construction method can be divided into NATM (New Austrian Tunnelling Method) and TBM (Tunnel Boring Machine). The NATM is a reliable method, but it is accompanied by vibration and noise due to blasting. In the case of the TBM excavation method, there are disadvantages in terms of construction period and construction cost, but it is possible to improve economic feasibility by introducing appropriate complementary methods. In this study, a blasting method was develop using the NATM after TBM pre-excavation using the protective shield method. This is a method that compensates for the disadvantages of each tunnel construction method, and is expected to reduce construction costs, blasting vibration, and noise. In order to review the performance of the developed method, an experiment was conducted to evaluate the performance of explosion-proof tube to which a protective shield scale model was applied, and the impact of blasting vibration of the protective shield method was analyzed.