• Explosives and Blasting
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• v.31 no.1
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• pp.55-63
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• 2013

With increasing needs in power, Singapore is requiring stronger power transmission. Singapore Transmission Cable Tunnel is underground tunnel for transmission system installation such as 400 kV cable. This Transmission Cable Tunnel is 35 km long in total. The North-South Transmission Cable Tunnel is 18.5 km long and there is a total of three (3) contracts; NS1, NS2 and NS3 in respect of the design and construction. The East-West Transmission Cable Tunnel is 16.5 km long, and also there is a total of three (3) contracts; EW1, EW2 and EW3. Among of them, SK E&C has been awarded and operating contract EW2 and NS2. In scope of works, each contract has 3 to 4 shafts which connect aboveground and underground high volt cable and those shafts are used as TBM launching shafts during construction. Transmission Cable Tunnel is undercrossing middle of Singapore and most of shafts are located in urban area. Thus, optimal blasting design satisfying high blasting efficiency as well as blasting vibration limit of Singapore is highly required. Blasting design for large shaft of Singapore Transmission Cable Tunnel follows blasting vibration limits in Singapore and reflects our blasting engineering skills. With Singapore Transmission Cable Tunnel Contract EW2, it is expected that our excellent blasting engineering and performance skills can be delivered to the world.

• Explosives and Blasting
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• v.28 no.2
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• pp.119-132
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• 2010

There are many dispute with a construction due to such environment problem as vibration and noise. Generally, we have a standard for acceptance level in land. But we have not a sufficient standard for acceptance level or guide line in underwater sound. In other countries, a acceptance level or guide line in underwater sound has been suggested. Especially the management criterion of underwater noise for fish has bee suggested using the measurement data (peak pressure, rms, energy and SEL) by a hydrophone. In Korea, there is no management criterion of underwater noise for fish. This study suggested the management criteria of underwater noise for fish based on the measured data by a hydrophone.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.235-240
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• 1997

터널발파는 벤치발파와 달리 일반적으로 심발발파, 주변공발파, 조절발파를 적용하는 최외곽공 발파로 나눌 수 있는데, 본 연구에서는 심발공법별 터널발파의 진동특성을 자유면의 수를 고려하여 해석하였다. 또한 터널발파의 발파효율에 가장 큰 영향을 미치는 심발발파 발파공들간의 지연지차를 서로 달리하면서 시험발파를 수행하였다. 국내 고속전철 건설현장의 터널발파시 측정한 진동속도의 파형분석결과 1자유면 발파인 심발발파시 발생하는 발파진동이 2자유면 발파인 주변공 발파시 발생하는 발파진동보다 30% 이상 더 크게 나타났고, 조절발파용 화약을 사용한 최외곽공 발파의 경우는 주변공발파보다 20% 정도 작은 진동속도를 나타내었다. 심발공법별 비교에서는 SUPEX-Cut의 경우가 국내에서 가장 널리 사용되는 V-Cut에 비해 20-30% 정도 더 작은 진동속도를 나타내었다. 또한 심발공들을 동시에 발파한 경우와 각 발파공의 시차를 서로 다르게 한 경우의 심발 시험발파 결과를 분석한 결과, 발파공간의 발파시차를 60msec 이상으로 하였을 때, 각 발파공의 발파시 발생한 진동이 서로 중첩되는 것을 방지할 수 있는 것으로 나타났다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.485-492
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• 2005

Since blast-induced vibration may cause serious problem to the rock mass as well as the nearby structures, the prediction of blast-induced vibration and the stability evaluation must be performed before blasting activities. Dynamic analysis has been Increased recently in order to analyze the effect of the blast-induced vibration. Most of the previous studies, however, were based on the continuum analysis unable to consider rock joints which significantly affect the wave propagation and attenuation characteristics. They also adopted pressure curves estimated by theoretical or empirical equations as input detonation load, thus there were very difficult to reflect the characteristics of propagating media. In this study, therefore, we suggested a discontinuum dynamic analysis technique which uses velocity waveform obtained from a test blast as an input detonation load. A distinct element program, UDEC was used to consider the effect of rock joints. In order to verify the validity of proposed method, the test blast was simulated. The predicted results from the proposed method showed a good agreement with the measured vibration data from the test blast Through the dynamic numerical modelling on the planned road tunnel and slope, we evaluated the effect of blast-induced vibration and the stability of rock slope.

• Explosives and Blasting
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• v.22 no.3
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• pp.71-78
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• 2004

Explosive blasting, hydaulic power unit and rock splitter are typically utilized for rockmass breakage and cutting in reconstruction of building structures and other construction site. Hydraulic rock cutting method, that can be utilized any weather conditions, has been applied mainly by experience for controling damages caused by vibration, noise and rock cuttings, and reducing damage claim by protecting adjacent structures. However, it is required to understand the characteristics of rockmass to improve operation efficiency. Although every cutting method has its own advantage, but it should be applied by considering site circumstance and rockmass properties in details to maximize the operation efficiency and economic feasibility.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.55-63
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• 2010

Although the environmental conflicts regarding noise and vibration are continually increasing during construction, noise and vibration occurring in construction are only managed in construction phase. Noise and Vibration occurring in construction are considered to be insufficient, so we find that noise and vibration management in design phase has to be operated for reducing. The objective of this paper is to present noise and vibration management lists to consider in design phase for enhancing efficiency in noise and vibration management and to develop the appraisal sheets for designers to evaluate and the manuals to easily use management lists. To achieve this, we identify the noise and vibration management lists to consider in design phase through analyzing the previous literatures and confirm the 9 lists through conducting a research with experts in environmental area for verifying the propriety of lists. Also, this study applies to AHP technique to identify the priority and the weight evaluation among the lists. Through this study, we identify the most efficient lists, including from the low noise and low vibration methods, the noise and vibration reduction by blasting works, the installment and the arrangement of noise and vibration control equipments, for noise and vibration management in design phase. The achievement of this study will help to prevent the environmental disputes and conflicts in advance and will consider utilizing for the successful construction project.

• Explosives and Blasting
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• v.34 no.3
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• pp.10-16
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• 2016

Recently, transition from open pit to underground mining in limestone mines is an increasing trend in Korea due to environmental issues such as noise, dust and vibrations caused by crushers and equipment. The severe damages in the surrounding rock mass of underground opening caused by explosive blasting may lead to rock fall hazards or casualties. It is well known that variables which mainly affect blast-induced rock falls in underground mining are: blast vibration level, joint orientation and distribution and shape of the cross sections of underground structures. In this study, UDEC program, which is a DEM code, is used to simulate blast vibration-induced rock fall in underground openings. Variation of joint space, joint angle and joint normal stiffness was considered to investigate the effect of joint characteristics on the blast vibration-induced rock fall in underground opening. Finally, jointed rock mass models considering blast-induced damage zone were examined to simulate the critical blast vibration value which may cause rock falls in underground opening.

• Explosives and Blasting
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• v.13 no.4
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• pp.5-27
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• 1995

Korea-America tungsten treaty is not only Earnning Us Dollar but also it was turnning point of tunnelling technology development such as a burn cut. Because 10th of specialist worked at Sangdong mine under treaty. The first of all, Experimental blasting pattern for single free face carried out. As a result it has brought the burden and $charge/m^3$ and also space distance. After the center holes are blasted. Remain of the works was the implementation of bench cut against the openning to make the full sectional are required. $Ca=\frac{A}{SW}$ where as A =ndi=m activated area S = Peripheral length of Charged room Ca = Rock Coefficient di=Holes diameter Later in 1980, The Oynaite Explosive is Replaced into Emulsion & Milli-Second Delay Electric Cap. Seqential Blasting machine were Applied in the Site. The Subway Tunnelling have been worked so Carefully for Vibration and Noise to near Shopping and housing area. We carried out Empirical formula to solve city Envoirement pollution as follow For Granite: $V=KW^{0.57}D^{-1.75}$ For Granite : $V=KW^{0.5}D^{-1.5}$ V=PPV(cm/sec) K=Coefficency D=Distance(m) W=Amount of power/delay(kg)

• Explosives and Blasting
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• v.24 no.2
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• pp.75-82
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• 2006

Most of limestone mines in Korea have been developed by a open-cut mining method in consideration of a deposited condition of ore, ore recovery, safety, economic efficiency, etc.. But it has produced environmental problems such as dust flying, blasting noise & vibration, and spoil of farmlands due to slope failure of waste rock mass caused by access road construction, fragmentation & crush of rocks, blasting, transportation, and mineral processing. In this study, it has been suggested for measures to reduce mine hazards caused by open- cut mining of limestone nines.

• Explosives and Blasting
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• v.27 no.1
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• pp.47-52
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• 2009

Blasting is necessary for excavation processes since more than 70% of korean land is consist of mountains. The vibration and noise accompanied by blasting processes usually bring about public complaints. Blasting patterns are chosen by economical efficiency, stability and construction conveniency. However, there are many alternatives without control to settle the popular complaint. To prevent those alternatives, standard blasting method for design and construction were suggested by MLTM (Ministry of Land, Transport and Maritime Affairs) in 2006. However, standard blasting pattern of MLTM was designed in a lump irrespective of types of rocks. Economical loss may occur by ignoring the characteristics of rocks for the applications to the rocks with low intensity, such as shale, or containing many joint. We deduced some economical progresses by performing test blasting with adjusted drilling spacing and length of burden considering the characteristics of local rock. This paper suggests the start of case studies for different applications. Economic improvement can be expected by applying those results deduced from case studies to design and construction.