• Explosives and Blasting
• /
• v.31 no.1
• /
• pp.76-86
• /
• 2013

In order to control tunnel blast vibration for adjacent facilities using electronic detonator, Understanding about the characteristics of near-field ground vibration is necessary. The purpose of this paper is to analyze effects of Cut-area and Extension-area vibration in relation to decision of tunnel blast vibration. These data were obtained at the top monitoring positions while ${\bigcirc}{\bigcirc}{\bigcirc}$ tunnel site of "Wonju~Gangneung double railroad section ${\bigcirc}{\bigcirc}$ construction" was passing under the existing road. Thus, tunnel blasting was conducted by tunnel electronic blasting system with 0.01% high delay-time accuracy. It can be possible that not only keeping maximum charge per delay-time but also preventing amplification of vibration which is occurred by delay-time scatter using common detonators. Additionally, V-Cut was changed into Burn-Cut. The results was presented that vibration level of extension-holes were higher than Cut-holes. Therefore, near-field ground vibration can be effectively minimized using electronic detonators in the Cut area. And also more effective way to reduce tunnel blast vibration is full-face blast using electronic detonators.

• Explosives and Blasting
• /
• v.30 no.2
• /
• pp.9-20
• /
• 2012

These days, mining industry prefers underground development for large mining because of exhaustive minning resources and large drafts and mining cavities thanks to extensive distribution of heavy excavation machines. In a mining design, to control collapse of cavities and secure stability, design of cavities and pillars are considered as very important. Therefore, this study obtained a prediction equation of blasting vibration through instrumentation for underground cavities. And we obtained theoretical shock vibration imposed on pillar through fragmentation analysis and measurement of flyrock distance. To examine the influence of pillar in underground mining blasting, we carried a finite element analysis and compared the result with prediction equation of blasting vibration, and shock vibration of flyrock when a impact was imposed on pillar and theoretical shock vibration.

• Explosives and Blasting
• /
• v.19 no.4
• /
• pp.11-22
• /
• 2001

토목공사장에서 암파쇄 작업은 경제성과 안정성에 지대한 영향을 미치는 작업이다. 본 논문은 대전지역에서 수행된 암파쇄 공법 설계 및 시공사례로서, 현장암반의 특성을 고려한 적정발파공법을 선정하기 위하여 대상 지역의 지질현황을 조사·분석하고, 또한 민원이 첨예한 도로개설 공사장에서 시험발파를 실시하여 이를 토대로 암절취 공법을 선정하여 시공한 사례보고이다. 대전지역의 지질은 선캠브리아기의 변성암류와 변성퇴적암류 및 이를 관입한 심성암류와 중생대 화강암으로 이루어져 있는 복잡한 분포를 이루고 있다. 사례연구 대상 현장은 편상구조가 현저한 관입 편상화강암 및 화강암질 편마암으로 구성되어 있었으며, 시험발파 및 분석결과를 기초로하여 25.5m이내 지역은 HRS 등 무진동 파쇄공법의 적용을 제안하였고, 25.5∼36m 범위의 대부분 지역은 진동제어를 할 수 있는 제어발파공법을 권장하였고, 기타 진동 영향권에서 비교적 안전한 것으로 나타난 지역은 소발파공법을 적용하도록 제안하였다. 제안된 안에 따라 설계를 보완하고 시공한 결과 문제의 발생없이 성공적으로 시공이 완료되었다.

• Explosives and Blasting
• /
• v.22 no.3
• /
• pp.35-41
• /
• 2004

Many buildings have been bolt in Korea. Because blasting operations and more efficient to make excavate rock than other methods, it's more extensively used for new construction, enlargement of buildings, subway work, etc. However, blasting vibrations and sound often create pollution. A study, 'The place of gathering earth and sand to construct a building site in Yangsan', has been done in Gyo-dong, in Yangsan. There are two high-rise apartment and buildings, beside a construction site. The blasting vibrations and sound were monitored on the 1st, 4th floors in building(4th floor), and the results of the analysis are as follows: The blasting vibrations decreased being transmited from 1st floor to 4th floor.

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

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.1
• /
• pp.100-108
• /
• 2017

Because of urbanization, Industrialization and expansion of transportation network, blasting works are recently increasing in construction field. The blasting work influences environmental effects to residents and the safety of facilities around the working place, so the development of blasting technology is needed to reduce the damage to residents. The blasting mechanism in the hole was studied and tested in the blasting sites by the difference of diameter between explosives and drilling hole, which is named by the decoupling effect. This effect was tested by changing the medium between explosives and hole wall in three working sites(railway, highway and industrial complex). The vibration velocity of blasting was recorded and vibration equations were produced by regression analyses. Finally, the structure separation distance was derived using these equations. The testing results show that the specific gravity of medium is larger, the separation distance is smaller and the duration time of blasting is shorter in case of large specific gravity of medium, so the vibration effect stops more fastly in the water compared with the air.

• Explosives and Blasting
• /
• v.32 no.2
• /
• pp.1-8
• /
• 2014

In this study, 16 test blastings had been carried out with different spacings, burdens, drilling lengths, and charges per delay for investigating the characteristics of ground vibration propagation, which depends on the delay time. From the tests, it was possible to derive a ground vibration equation. Using the equation, the characteristics of ground vibration could be investigated by analyzing the nomogram and predicting the Peak Particle Velocity (PPV), which are influenced by the delay time and the priming location. The trend of ground vibration change depending on the delay time was analyzed for the standards charges of 0.5, 1.6, 5, and 15 kg, which were suggested in "Blasting design and construction guidelines to road construction" by the Ministry of Land, Infrastructure and Transport. From the study, it would be possible to suggest a favorable vibration control method, which depends on the charge.

• Explosives and Blasting
• /
• v.18 no.2
• /
• pp.7-13
• /
• 2000

Abstract The characteristics of bed rock in the study area was classified by means of the crack coefficient estimated from the seismic velocities of in-situ and intact rocks. Various statistical methods were investigated in order to minimize the possible errors in estimating the predictive equation of blasting vibration and to enhance the determination coefficient $R^2$, for more reliable estimation. The determination coefficient showed the highest in the analysis for those groups using weighting function with the number of samples. The analysis for the weighting function employed with standard coefficient and variance also enhanced the determination coefficients significantly compared to the others, but the reliability was slightly lower than results obtained former method. Therefore the most reliable predictive equation of blasting vibration was found to be obtained from a regression analysis of the mean vibration level using the weighting of same distance groups within 15m with the same explosive charge weight per delay. The coefficients, K and n 317.4 and -1.66, respectively, when using the square root scaling, and 209.9 and -1.66, respectively, when using the cube root scaling. The analysis also showed that the square root scaling may be used in the distance less than 31m form the blast source, and the cube root scaling in the distance more than 31m for safe design.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.3
• /
• pp.71-86
• /
• 2023

Rock blasting tests using underground penetration-type displacement sensors were conducted, and three-dimensional finite element numerical analyses were performed to assess their applicability and mitigate slope hazards during rock blasting. Additionally, parameters influencing vibration velocity were investigated during the tests. The results confirmed that underground penetration-type displacement sensors are suitable for monitoring rock slope behavior, and the numerical analyses revealed that the most influential parameter on vibration velocity during rock blasting is the unit weight. Furthermore, it was observed that vibration velocity decreases significantly with distance from the blast source, and proximity to the source leads to substantial variations in vibration velocity due to differences in elastic modulus and unit weight. Changes in internal friction angle and adhesive strength had minimal impact.

• Explosives and Blasting
• /
• v.32 no.2
• /
• pp.25-30
• /
• 2014

Although the construction noise and vibration are transient and intermittent, their impact on the surrounding environment is huge. Since the construction equipment noise and vibration is usually transmitted because of the long distance, the sound insulation and the proper design of anti-vibration measures are very difficult. The regulation requires that the noise and vibration caused by the construction equipments should be measured within 30m from the source, whereas the blasting noise and vibration should be measured at least 60m and 160m away from the source, respectively. Instead of the 2D modelling mainly conducted so far, the 3D analysis of noise and vibration with the consideration of the height and size of the building, mountains and hills in the vicinity of the source is necessary.