• 한국가스학회지
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• 제5권2호
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• pp.30-35
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• 2001

현재 운용중인 가스배관은 다양한 건설진동에 의하여 영향을 받고 있다. 특히 지하철 공사 및 도로공사 시에는 건설장비의 사용, 대형차량의 통행 및 발파 등으로 인해 발생되는 건설진동이 가스관에 큰 영향을 미친다. 매설가스관의 경우는 매설된 위치와 근접한 곳에서 시행되는 발파로 인한 진동영향이 큰 상태이며 노출가스관의 경우는 차량진동에 대하여 가장 크게 영향을 받고 있다. 본 논문에서는 가스배관 주변에서 발생하는 건설진동을 측정, 분석함으로써 건설진동에 의한 가스배관의 진동을 손쉽게 예측할 수 있는 가스관 진동예측 프로그램을 소개하였다. 이 프로그램은 가스관의 진동을 예측하는 소프트웨어로 기존의 신뢰성 분석된 경험식과 유한요소해석을 통한 구조해석 결과를 이용하여 매설 및 노출 가스관에서의 진동치를 현장조건에 따라 예측할 수 있고, 측정된 진동데이터를 데이터베이스화 할 수 있는 기능을 가지고 있다. 또한 현장에서 발파진동을 측정하여 발파진동추정식을 산정하고, 지발당 허용장약량을 나타내는 그래프를 자동으로 형성할 수 있는 기능을 가지고 있다. 따라서 현장 근무자가 손쉽게 가스관 주변에서 진동을 예측하여 가스관의 안전성을 평가할 수 있다.

• Structural Engineering and Mechanics
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• 제33권1호
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• pp.79-93
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• 2009

This paper investigates the possibility of controlling the response of typical portal frame structures to blast loading using a combination of semi-active and passive control devices. A one storey reinforced concrete portal frame is modelled using non-linear finite elements with each column discretised into multiple elements to capture the higher frequency modes of column vibration response that are typical features of blast responses. The model structure is subjected to blast loads of varying duration, magnitude and shape, and the critical aspects of the response are investigated over a range of structural periods in the form of blast load response spectra. It is found that the shape or length of the blast load is not a factor in the response, as long as the period is less than 25% of the fundamental structural period. Thus, blast load response can be expressed strictly as a function of the momentum applied to the structure by a blast load. The optimal device arrangements are found to be those that reduce the first peak of the structural displacement and also reduce the subsequent free vibration of the structure. Semi-active devices that do not increase base shear demands on the foundations in combination with a passive yielding tendon are found to provide the most effective control, particularly if base shear demand is an important consideration, as with older structures. The overall results are summarised as response spectra for eventual potential use within standard structural design paradigms.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.136-137
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• 2010

• 산업기술연구
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• 제20권A호
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• pp.269-278
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• 2000

The pressure-time profile of the explosion gases can controlled for the use of cartridge explosive with two techniques known as Decoupling and spacing of the charges. Decoupling consists of a space between the explosive column and wall of the blast hole. Four different decoupling index 1.4, 1.8, 2.34, 3.0 are selected in this field study. The level of ground vibrations with each decoupling index was measured and the empirical particle velocity equation from these data was obtained. The condition of new cracks at blast hole are also examined. As the decoupling index is increased, the level of the blast vibration is decreased. But the cracks in rock masses are efficiently formed to remove the broken rock. The vibration constant associated with test sites is given as $K=1564.5(D.L)^{-1.3233}$ in terms of D.I.(decoupling index).

• 터널과지하공간
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• 제5권2호
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• pp.89-94
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• 1995

Regression analysis and a comparative study were carried out for 52 blast vibration data which were monitored by changing the monitoring distance and charge per delay. The results are as follows: 1) The square and cube root scalings and general equation which have a confidence level at the point of 90% and 99% are V90=33300(SD)-2.026 , V90=23600(SD)-1.993, V90=26300W0.755 R-2.007 and V99=48400(SD)-2.026, V99=34000(SD)-1.993 , V99=38100W0.755R-2.007, respectively. 2) There is need to decide the allowable max. charge weight per delay considering the cross points comparatively of the nomogram constructed using several predictived equations. 3) It is necessary to derive the predictive equation on the basis of blast vibration level monitored in field and to decide safe vibration level and the confidence level.

• Geomechanics and Engineering
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• 제11권3호
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• pp.421-438
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• 2016

Explosions inside transportation tunnels might result in failure of tunnel structures. This study investigated the failure mechanisms of circular cast-iron tunnels in saturated soil subjected to medium internal blast loading. This issue is crucial to tunnel safety as many transportation tunnels run through saturated soils. At the same time blast loading on saturated soils may induce residual excess pore pressure, which may result in soil liquefaction. A series of numerical simulations were carried out using Finite Element program LS-DYNA. The effect of soil liquefaction was simulated by the Federal Highway soil model. It was found that the failure modes of tunnel lining were differed with different levels of blast loading. The damage and failure of the tunnel lining was progressive in nature and they occurred mainly during lining vibration when the main event of blast loading was over. Soil liquefaction may lead to more severe failure of tunnel lining. Soil deformation and soil liquefaction were determined by the coupling effects of lining damage, lining vibration, and blast loading. The damage of tunnel lining was a result of internal blast loading as well as dynamic interaction between tunnel lining and saturated soil, and stress concentration induced by a ventilation shaft connected to the tunnel might result in more severe lining damage.

• 터널과지하공간
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• 제17권3호
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• pp.216-224
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• 2007

화약의 동적 충격에너지를 이용하는 발파굴착은 매우 효율적인 터널굴착방법이다. 그러나 진동과 암소음 등의 발파공해가 발생하는 문제점이 있다. 최근 연구를 통해 노치공을 이용한 선균열 암굴착방법은 발파공해와 터널의 여굴을 상당히 줄일 수 있는 것으로 확인되었고 이에 따라 본 연구에서는 노치발파공의 성형을 위한 노치장비개발에 관한 연구를 수행하였다. 노치공을 효율적으로 성형하기 위해 노치비트의 길이, 높이 등을 다양하게 변화시켜 실험을 수행하여 최적화하였고, 천공속도, 천공정밀도를 높이기 위한 천공비트, 노치비트, 아답타, 노치 가이드로 이루어진 노치비트 시스템을 개발하였다.

• 한국터널지하공간학회 논문집
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• 제8권2호
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• pp.129-139
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• 2006

두개의 장약공에 시차를 주고 발파할 경우 파의 특징인 상호 간섭현상이 발생한다. 이러한 파의 간섭현상은 중첩을 통하여 파가 서로 증폭이 되거나 상쇄가 된다. 따라서 이러한 파의 특성을 이용하여 시험발파 시 단공발파를 통한 발파진동 데이터를 측정하여 각각의 파형을 합성한 뒤 최적지연초시를 찾고 이 합성초시를 전단면에 적용하여 그 효율성을 입증하는데 이번 실험의 목적이 있다. 기존뇌관(비전기, 전기뇌관)의 정형화된 초시(20, 25ms)가 아닌 현장암질에 적합한 전자뇌관의 최적초시를 도출하여 발파 진동을 최소화 하고 굴착효율을 높이는 발파 굴착공법의 개발을 모색하고 시험시공을 통한 현장 적용성을 평가하였다.

• 화약ㆍ발파
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• 제30권2호
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• pp.21-28
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• 2012

사면 절취 및 도심지 터파기 등 인공적으로 사면을 형성하는 경우 경제적이고 효율적인 공법으로 화약을 이용한 발파공법이 많이 사용되고 있다. 절취면 보호를 위해 대상 암반에 손상을 주지 않고 암반이 가지고 있는 자연적인 강도를 그대로 유지할 수 있도록 발파하는 것이 중요하며 사회적으로 문제 시 되는 발파공해를 고려하여 발파진동을 저감할 수 있는 공법이 필요하다. 본 연구에서는 평활한 절취면 형성을 위하여 도폭선에 폭약을 등간격으로 배치하고 장약의 방법과 전색의 방법을 달리하여 발파를 진행하였다. 4가지 패턴을 사용하여 총 60공에서 20회 발파를 실시하였으며 발파원으로부터 15~120m 거리에서 발파진동소음측정기를 사용하여 진동속도를 측정하여 310개의 데이터를 획득하였다. 측정된 진동속도 데이터를 분석하여 발파진동을 저감하고 효율적이고 경제적으로 절취면을 보호할 수 있는 방법을 연구해 보았다.

• 화약ㆍ발파
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• 제23권2호
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• pp.57-66
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• 2005

A major concern with blasting at surface mines is generation of ground vibration, air blast, flyrock, dust & fume and their impact on nearby structures and environment. A study was conducted at a coal mine in India which produces 10 million tonne of coal and 27 million cubic meter of overburden per annum. Draglines and shovels with dumpers carry out the removal of overburden. Detonation of 100 tonnes of explosives in a blasting round is a common practice of the mine. These large sized blasts often led to complaints from the nearby inhabitants regarding ground vibrations and their affects on their houses. Eighteen dragline blasts were conducted and their impacts on nearby structures were investigated. Extended seismic arrays were used to identify the vibration characteristics within a few tens meters of the blasts and also as modified by the media at distances over 5 km. 10 to 12 seismographs were deployed in an array to gather the time histories of vibrations. A signature blast was conducted to know the fundamental frequency of the particular transmitting media between the blast face and the structures. The faster decay of high frequency components was observed. It was also observed that at distances of 5km, the persistence of vibrations in the structures was substantially increased by more 10 seconds. The proximity of the frequency of the ground vibration to the structure's fundamental frequencies produced the resonance in the structures. On the basis of the fundamental frequency of the structures, the delay interval was optimized, which resulted into lower amplitude and reduced persistence of vibration in the structures.