• Explosives and Blasting
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• v.34 no.3
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• pp.21-26
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• 2016

In case of urban blasting works at near neighbors, the size of one blasting should be minimized to reduce the vibration and noise. However, the complaints is not decreased due to increased numbers of blasting per day so that the period of blasting works become long. This case study is related to urban apartment construction site. In order to overcome the weakness of general detonators which is required many blasting times to meet the day productivity, we have been applied deck-charge blasting method using electronic detonators and then we successfully increased the day productivity with much less blasting times. Hence, we had effectively achieved the declined neighbors'complaints and shortening construction period.

• Explosives and Blasting
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• v.20 no.3
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• pp.59-71
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• 2002

The points of this design case are the planning and excavation method of a new double-tracked railroad tunnel which is approx. 11∼22 meters apart from existing single-tracked railroad tunnel. For the optimum excavation method some needs are required in design stage, such as the reduction of noise and vibration, public resentment, damage of buildings and construction costs. Hence the estimation and application of allowable noise and vibration criterion is important. The ground coefficient (K, n) of this site is determined by field trial blasting. The excavation method is chosen to satisfy the allowable noise and vibration criterion. In addition, in order to ensure the stability of existing single-tracked railroad tunnel, the instrumentation of maintenance level is accompanied during the construction stage. As a result of this design condition, central diaphragm excavation with line drilling and pre-large hole boring blasting is applied to the area within 15 meters apart from existing tunnel. And above 15 meters apart, pre-large hole boring blasting is designed.

• Explosives and Blasting
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• v.40 no.2
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• pp.25-34
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• 2022

Recently, there has been an increasing number of cases of improving constructability by using electronic detonators with precise delay time in tunnel blasting sites. This case is a case of conducting test blasting using with non-electric detonator and electronic detonator at the site of 『Seoul Metropolitan Area Express Railroad Route A Private Investment Project Section 00』 that requires careful management of vibration and noise. Although this site was designed with a non-electric detonator, it was attempted to improve the advance rate and control vibration and noise by mixing the non-electric detonator and the electronic detonator due to the decrease in the advance rate. As a result of the blasting, the target value was achieved with an advance rate of about 85% and a maximum measured value of vibration and noise is 0.215cm/sec and 73.22dB(A) which were measured below regulatory standards. As blasting works in downtown areas, it is necessary to designate measurement and management objects to continuously manage vibration and noise.

• 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.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.150-151
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• 2022

Blasting is a method that uses explosives to crush the ground. This method is a highly efficient ground cleaning method that can secure high efficiency in a short time. However, explosions can damage local properties and produce high noise and vibration. Therefore, it is important to be careful because there are disadvantages such as the occurrence of many complaints from the surrounding area. In this paper measured and analyzed the noise and vibration generated during blasting at the blasting site in Korea. The noise and vibration generated during blasting were measured by ES03303.2b and ES03402.2a at a distance of 6 m, 12 m from the blasting point. As a result of the measurement, there was little difference between small and medium scale except for precision vibration blasting at a distance of 6m, but noise difference according to blasting scale was evident at a distance of 12m. As a result of the measurement, the maximum noise level was reduced to 5.5 dB(A) and the vibration level was reduced to 7.7 dB(V). In the future, the reliability of the test results can be further improved through additional tests, and it is judged that noise and vibration prediction models based on blasting methods, amount of charge, measuring distance, etc. can be developed.

• Explosives and Blasting
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• v.9 no.3
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• pp.10-16
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• 1991

On the ground foundation works for Bldg site, Rock classification test can be obtained as follows due to the International Society for Rock Mechanics. 1. In-situ test : Compressive strength, Point load test. 2. In-situ test Schmidt hammer test. Burden test finaly the convinient co-relation table between strength and 5. H, test were carried out for site-engineer, This project is one of contineous works regarding to Burden test from Jack leg drill($\phi{\;}75mm$) use.

• Explosives and Blasting
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• v.10 no.2
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• pp.3-7
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• 1992

Concerning to Taeku city subway construction project(1-4 site), the original design was adapted NATM Tunnel method to the 8 meter thickness of overburden. Surveyor checked sity and design material and finally decided to change into Open Cut method because overburden is not only below 1 1/2 times thickness of comparate Tunnel width but there is no traffic conjunction in job site.

• Explosives and Blasting
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• v.10 no.1
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• pp.3-7
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• 1992

In the pilling works in the city, it is tend to transfered to the non-vibration pilling works. This drop-hammer pilling executed with in 2 meters distance to neighbour building structure. in the rainy season. According to imperical formula which tested in similar site, Vibration damaged area is within 14 meters radius from drop-hammer pilling site. The loratories Data of Dae Woo of Korea hausing Authority are refered to above poject.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.766-771
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• 2005

To compare blasting vibration at blasting construction field in urban area, the vibration level (dB(V)) and vibration velocity (cm/sec) on the ground and the structure of buildings due to the differences of the measuring sites from the blasting source is investigated and the difference between the measured vertical vibration level and the calculated vibration level by using vibration velocity PVS and the correlation between vibration velocity and vibration level and is studied in the thesis.