• Smart Media Journal
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• v.12 no.11
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• pp.67-76
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• 2023

We propose a visualization method to respond to civil complaints through an analysis of the impact of blasting. In order to analyze the impact of blasting on tunnel excavation, we propose a simulation visualization method considering the mutual influence of the construction infrastructure by linking measurement data and 3D BIM model. First, the level of BIM modeling required for simulation was defined. In addition, vibration measurement data were collected for the GTX-A construction site, terrain and structure BIM were created, and a method for visualizing measurement data using blast vibration estimation was developed. Next, a spherical blasting influence source library was developed for visualization of the blasting influence source, and a specification table that could be linked with Revit Dynamo automation logic was constructed. Using this result, a method for easily visualizing the impact analysis of blasting vibration in 3D was proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4790-4795
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• 2014

The machine tool is used widely to manufacture and trial manufactured goods in many machinery industries. Blast-induced ground vibration may have an environmental impact, such as damage to the adjacent structures and facilities. This study examined the influence of blast vibration on the accuracy of machine tools. The blast vibration and vibration of machine tools was measured to evaluate the influence of blast vibration on machine tools. Based on the evaluation of the vibration limit of machine tools, the vibration criteria for machine tools in this study were SLIGHTLY ROUGH~ROUGH. By repeated blast vibration, machine tools are more likely show reduced accuracy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.459-468
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• 2023

Power plant is a kind of basic industrial facility and might cause fatal industrial and human damage. In this study, the characteristics and effect of blast-induced vibration for tunnelling which underpass ○○ power plant in operation were evaluated. Previous blasting cases adjacent to industrial facilities were intensively reviewed, then allowable vibration criteria were suggested. 3 dimensional dynamic numerical analysis based on finite element method was performed to investigate particle velocity and resonance was examined by calculating the predominant frequencies. As a result, particle velocity at pump foundation which is nearest to the source was approached to the allowable criteria, therefore, the modified blasting pattern was newly suggested and confirmed the attenuation effect based on the test blasting. Consequently, appropriated decision-support procedure was established in case of adjacent blasting to industrial facilities.

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.327-345
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• 2020

The effects of ground vibration on lava tubes during construction were studied to aid design of management and preservation measures for lava tubes. Ground conditions were assessed by RMR (Rock mass rating) and Q-system classifications for the Geomunoreum lava tubes, and vibration velocity was measured during in situ blasting tests in the Manjanggul and Yongcheondonggul lava tubes. Results indicate that the higher the rock quality, the greater the effect of vibration, although there is no clear linear relationship due to ground heterogeneity. A relationship derived between vibration velocity (PPV) and intensity (dB(V)) on the basis of blasting tests indicates that a vibration level of < 0.285 cm/sec meets the regulatory limit of 0.371 cm/sec and 65 dB(V) during daytime, and 0.285 cm/sec and 60 dB(V) during night. For blasting vibrations, square- and cube-root scaled distances are linearly correlated, with R² ≥ 0.76. On the basis of this correlation, explosive-charge weights meeting the 0.2 cm/sec vibration criterion for cultural heritage were estimated to be 2.88 kg at 50 m distance, and 11.52 kg at 100 m.

• The Journal of the Acoustical Society of Korea
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• v.4 no.3
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• pp.21-32
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• 1985

서로 상관관계가 있는 다입력원 진동계의 진동원을 규명하기 위한 방법을 제안하였다. 다차원 스펙트럼 해석을 이용함으로써 지하철 진동의 가장 중요한 진동원을 발견하였다. 이 분석은 진동의 전 달경로가 매우 복잡할 때 다입력-단일출력으로 모델화 하여 분석하는 방법이다. 또한 레지듀 스펙트럼 분석과 부분기여함수의 개념을 적용하여 지하철 진동이 콘크리트 구조물의 진동에 미치는 영향을 마이 크로 컴퓨터로 계산하였다. 이러한 연구의 결과로 지하철 진동의 다차원 스펙트럼의 오버올레벨을 측정 치와 비교하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.46-51
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• 1994

자동차용 MCP(Multi Changer Player)는 조용하고 깨끗한 음악을 감상하고 싶어하는 소비자들에게 큰 호응을 얻고 있다. 그러나 주행중에 외력이 자동차용 MCP 데크를 통하여 클렘핑부(Clamping부 : 이하 방진부라 함)에 전달되어 방진부에 진동이 발생할 수 있다. 이때 방진부에 장착되어 있는 CD(Compact Disc)의 음재생에 영향을 줄 수 있다. 따라서 본 연구에서는 자동차용 MCP 데크 메카니즘의 중요 구성 부분인 방진부를 설계 및 실험 해석에 의해 진동 저감 대책을 세움으로써 기초 자료를 확보하고 제품의 성능을 향상시키고자 한다. 자동차용 MCP 데크에 장착된 방진부의 진동 저감 문제를 해결하기 위해 먼저 다음과 같은 사항이 방진부에 미치는 영향도를 알아본다. 1) 아이들링(Idling) 중일때의 자동차의 특성과 주행중일때의 자동차의 특성 및 노면 외란이 진장부에 미치는 영향도를 파악한다. 2) CD가 클램핌되어 있을 때의 CD의 모드를 해석해 본다. 그리고 방진재로 사용된 스프링의 설계 및 방진 고무의 물성치 변화에 따른 방진부의 특성변화를 실험에 의해 해석하여 적절한 방진재를 선정한다. 또한 결정된 방진재를 사용한 MCP의 음비(Sound Skip) 특성을 측정해본다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.295-301
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• 1997

본 연구의 목적은 수도권 전동차량의 주행성능을 평가하는 방법으로 진동성능을 비교검토하기 위하여 실차측정하고 분석한 것이다. 전동차량의 제작년도별로 측정대상차량을 샘플링하여 다양한 조건에서 진동을 측정하고 실측데이타를 시간영역의 통계적 방법으로 분석한 결과 제작년도에 따른 영향도 약간 나타났으며 전동차량의 2차 현가장치의 종류에 따른 영향을 발견할 수 있었다. 또한 측정선로구간의 특성에 따른 영향도 비교적 잘 나타나고 있음을 알 수 있었다.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.76-76
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• 2010

무연솔더 재료를 자동차 전장품에 적용하기 위해서는 고온환경에 대한 내구성 및 진동 인자에 대한 영향을 고려해야한다. 특히, ELV(End of Life Vehicles) 지침이 개정됨에 따라 고온용 무연솔더 재료에 대한 재평가가 반드시 필요한 시점이다. 이에 대해 본연구에서는 현재 상용화 된 Pb-free솔더의 재료들 중 총 4종의 Solder을 선정하여 자동차 환경에 부합하는 진동조건하에서 시험해보았다. 그리고 미세조직의 특성, 접합부 형성시의 기계적 강도 및 접합부의 신뢰성을 평가하여 보았다. 각각의 조성에 대한 CHIP type과 QFP type의 실장부품을 준비하였으며, 각각의 조성별로 솔더 페이스트로 Daisy Chain PCB에 접합하여 조성에 따른 비교 데이터를 구축할 수 있었다. 리플로우 공정후 초기의 미세조직 및 전당강도, 저항값을 측정하여 진동시험에 따른 데이터와 비교하였다. 주파수는 10Hz~1,000Hz였으며, 진동가속도는 $29.4m/s^2$, 20시간의 랜덤진동이 적용되는 동안 챔버내의 온도는 상온으로 유지되었다. 진동시험과 이에 따른 저항측정을 통하여 진동 주파수와 시간에 따른 실장 부품이 받는 진동 영향과 실시간 저항값을 측정하였으며, 이때의 미세조직 비교를 통해 진동특성을 평가하였다. 진동 주파수에 따른 저항값의 변화가 있었으며, 진동전후 전단강도에도 영향을 주었다. QFP type에서는 SAC105가 진동에 가장 취약하였으며, CHIP type에서는 SACX0307이 진동에 가장 취약하였다.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.41-53
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• 2022

In the excavation work like blasting/excavator work bordering on the urban railway, the dynamic safety of railway structures like tunnel, open-cut box structure and elevated bridge was investigated by numerical analysis in this study. The practically presented criteria on influential zones at the blasting work in the construction industry was numerically checked in cases of the precise vibration-controlled blasting (type II) and the small scale vibration-controlled blasting (type III) and it was shown that the criteria on blasting work methods needed to be supplemented through continuous field tests and numerical analyses. The influence of excavation vibration by mechanical excavators was especially investigated in case of earth auger and breaker. The numerical analysis of tunnel shows that the criteria on vibration velocities from the regression analysis of field test values was conservative. The amplification phenomenon of excavating vibration velocity was shown passing through the backfilling soil between the earth auger and the open-cut box structure. It was shown that the added-vibration on the superstructure of elevated bridge was occurred at the bottom of pile like earthquake when the excavator vibration was arriving at the pile toe. The systematic and continuous research on the vibration effect from excavating works was needed for the safety of urban railway structures and nearby facilities.

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.273-297
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• 2005

In construction site, there are some occasions where concrete under initial curing is being affected by nitration from nearby vibration sources. To study these effects, in this paper, strength characteristics of concrete specimens subjected to continuous vibration up to 12 hours in vertical direction after concrete placement were observed. And through the vibration time control experiment where a number of time combinations consisted of times before and after applying vibration during initial curing period were used as experimental parameters, possibility of concrete strength improvement was investigated. From the experimental results, it could be seen that the concrete strengths were mostly decreased due to the increase of vibration velocity during initial curing period. But fluctuation ratio of concrete strength did not have any close correlations with the vibration times. And results of vibration time control experiment showed that if times before applying vibration sustains at least more than 3 hours, subsequent vibrations after that hours do not affect the concrete strength in any unfavorable ways.