• Title/Summary/Keyword: allowable vibration velocity

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The Prediction of Allowable Limit Distance about Human Body by Vibration Regulation (진동 규제기준에 따른 인체의 허용 한계거리 예측)

  • Song, Jeong-Un;Hong, Woong-Ki;Kim, Seung-Kon
    • Journal of Environmental Impact Assessment
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    • v.21 no.2
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    • pp.289-296
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    • 2012
  • The shock vibration such as machine vibration, blasting vibration etc. has effect on nearby structure as well as human body. The purpose of this study is to predict allowable limit distance of vibration about human body. First of all, vibration velocity such as PPV, PVS was measured by shock vibration experiment, and vibration level was calculated by conversion formula of vibration velocity. And then, allowable limit distance was analyzed by converted vibration level. The results are as follows : Firstly, the correlation coefficient of converted vibration level was over R=0.94, and vibration level caused by PVS was usually represented to high curve line. Secondly, the cross point of vibration level between ground and concrete condition was represented to 66.68dB(V), and allowable limit distance was represented to difference over three times when vibration regulation was raised from 65dB(V) to 80dB(V).

Vibration Reducing Method for High Pressure Feedwater Heater Drain Piping System (고압급수가열기 배수계통 배관계 고진동 해소방안 연구)

  • Lee, Wook-Ryun;Lee, Jun-Shin;Kim, Sang-Bok;Hong, Soon-Bup;Shin, Yong-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.1290-1295
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    • 2006
  • The 120 meters high pressure feedwater heater drain piping in nuclear power plant had been suffered by excessive vibration from the beginning of power generation. As time goes by, the piping vibration was beyond the allowable limit and an appropriate countermeasure was required to prevent the fatigue failure of the pipeline from the abnormal vibration. In this study, the vibrational characteristics of high pressure feedwater heater drain piping and the countermeasure for abnormal vibration were investigated. Among the several vibration reduction methods, the piping layout changed by making the smooth pipeline was applied to the high Pressure feedwater heater drain piping in nuclear Power plant. Applying the countermeasure, the vibration level was found to reduce over 54 percents and was satisfied under the allowable velocity at the full-power operation condition.

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Case Study for Compaction in the Vicinity of Structures in Inchon International Airport Civil Construction (인천국제공항 공항토목시설공사 구조물주변 다짐시공 사례 연구)

  • 최인걸;신종순;김동수;성낙일
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.455-462
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    • 1999
  • In this case, we have selected a representative location in the vicinity of large underground structures where they cross a runway and taxiway: measured the effects of the dynamic hammer compaction by distance: analyzed the measured results over a period of time and for many frequencies: and determined the maximum anticipated particle velocity (PV) of vibration, caused by the dynamic hammer, verses distance. In addition, while compacting the hydrofill, we reviewed the impact of subsurface particle velocities, caused by hammer compaction methods, upon newly constructed reinforced concrete underground structures. We have implemented the appropriate technical standards after reviewing domestic and international technical standards concerning allowable vibration velocity appropriate In the many types of underground structures at Inchon International Airport.

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A Study on the Ground Vibration of the Front and the Back Direction of the Free Face in the Bench Blasting (계단식 발파에 있어서 자유면 전.후방의 지반진동에 관한 연구)

  • 기경철;김일중
    • Explosives and Blasting
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    • v.20 no.2
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    • pp.21-31
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    • 2002
  • We did bench blasting upon the natural rock which it's uniaxial compressive strength was about $1,420~1,476kgf/\textrm{cm}^2$. This is the results we inferred after measuring, analyzing the ground vibration velocity of the front and back direction from the free face of the bench blasting. We have to induce the square and cube root scaled equation and the general equation to guarantee confidence upon the data when analyzing the measurement data of the test blasting. The variable distance is in reverse proportion to the permitted ground vibration velocity. The shorter is the exploding point to a protection structure, the bigger is the reflection that the direction of the free face experts the ground vibration velocity, The ground vibration velocity front of the free face tends become reduced about 38~46% compare with back of the free face in the range that the permitted ground vibration velocity is 2.0~5.0mm/sec. In case of 2.0mm/sec, when a protection structure is within about 95m, the max. allowable charge weight per delay on positing front of the free face can be more used about 2.61 times than that on positing back of the free face, in case of 3.0mm/sec within about 78m more about 2.38 times, in case of 5.0mm/sec within 60m more about 2.10 times. In case of 2.0~5.0mm/sec when a protection structure is within about 200m front from the free face, the max. allowable charge weight per delay can become about 1.52 times than the case on back to the free face.

A Safety Evaluation Study by Vibration Analysis for Shutdown Cooling Piping System (원전 정지냉각계통 배관 진동안전성 평가연구)

  • Lee, Wook-Ryun;Lee, Jun-Shin;Sohn, Soek-Man;Kim, Man-Hee;Song, Seong-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.41-45
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    • 2007
  • Palo Verde Unit 1 nuclear power station which is located in Arizona, USA had been operating at reduced power levels around 25% since December 25, 2005 due to vibration in one of its shutdown cooling lines. During an outage from March 18, 2006 to July 7, 2006 the necessary work and modifications to remedy the situation were performed. It cost approximately $46million to buy electricity to replace that lost as a result of this event. Therefore in this study, the vibration of shutdown cooling lines in the same nuclear power plant in Korea as Palo Verde Unit 1 should be measured by the operating condition of power plant. And it was evaluated using the expression for allowable velocity in ASME OM-S/G-2003. From the result of this study it is evaluated whether it is safe or not. If not the countermeasure should be considered in this study.

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Stability Assessment of Concrete Lining and Rock Bolts of the Adjacent Tunnel by Blast-Induced Vibration (발파진동이 인접한 터널의 콘크리트 라이닝과 록볼트의 안정성에 미치는 영향평가)

  • Jeon, Sang-Soo;Kim, Doo-Seop;Jang, Yang-Won
    • Journal of the Korean Geotechnical Society
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    • v.23 no.10
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    • pp.33-45
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    • 2007
  • In this study, the blast-induced vibration effects on the structural stability of the adjacent tunnel were estimated with respect to the allowable peak particle velocity (PPV). The blasting distance from the tunnel satisfying the allowable PPV was estimated based on the analytical solutions, United States Bureau of Mines (USBM) suggestions, and the equations used in the subway in Seoul. The allowable blasting distance was estimated by using finite difference analysis (FDA) and the behavior of the concrete lining and rock bolts was examined and the stability of those was estimated during the blast. Research results show that the blast-induced vibration effects on the structural stability are negligible for the concrete lining but relatively large for the rock bolts.

Analysis and Evaluation of the Effect of Blast-induced Vibration Adjacent to Industrial Facilities (산업시설 근접발파 시 발파진동 영향 분석 및 평가)

  • Kawk, Chang Won;Park, Inn Joon;Kim, Young Jun
    • 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.

Review of National Standards for Allowable Limit of Blast Vibration on Structures (구조물에 대한 국외 발파진동 허용 규제기준 분석)

  • Ryu Chang-Ha
    • Explosives and Blasting
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    • v.23 no.3
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    • pp.1-10
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    • 2005
  • Blast-induced ground vibration nay cause an environmental impact such as neighbour's complaints or damage on adjacent structures and facilities. Complaints associated with blasting have often become a target of public grievances. One of the difficulties to solve the problem is that we do not have a national standard for the acceptance level of blast-induced ground vibration. A peak particle velocity criterion, which was suggested for urbane underground construction, has often been widely used. Efforts have been made to establish more rational criteria. It seems that differing cultures have often differing thresholds of the toleration of vibration, and that technical data or rational grounds for establishing the limits are hardly provided. In this paper, national standards for allowable limit of blast vibration were presented and discussed.

Dynamic Characteristics of Buried Pipeline under Vibration Velocity of Vehicle Loads (도로 하부 통과 배관의 주행 하중 속도에 따른 진동 특성)

  • Won, Jong-Hwa;Sun, Jin-Sun;Yoo, Han-Kyu;Kim, Moon-Kyum
    • Journal of the Korean Institute of Gas
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    • v.12 no.1
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    • pp.13-18
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    • 2008
  • Vibration velocity induced by earthquakes or external vibration sources is one of the integrity assessment indexes, and is also a representative value used to describe the amount of vibration because it is based on a proportional relationship with the damage scale. In this study, the vibration velocity criterion for structures is first examined. Then, based on the velocity criterion, an integrity assessment is performed. Burial condition is set up based on the "Highway and Local Road Design Criteria" with API 5L Gr. X65 pipeline(D=762 mm). The FE model considers DB-24 vehicle load as a time function with a varying velocity in the range of $20{\sim}160\;km/h$. Maximum vibration velocity occurs at v=80 km/h and decreases after v=80 km/h. The maximum vibration velocity of buried pipeline by DB-24 loads is about 0.034 cm/s. The velocity that occurs is in the range of allowable values for each vibration velocity criterion. The wave propagation velocity was identified based on attenuation law and the minimum value appears at vehicle velocity 80 km/h that has maximum vibration velocity.

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Environmental Effects and Characteristics of Ground Vibration Caused by Tunnel Blasting in the Vicinity of an Apartment (터널 발파로 인한 아파트 인근지역에서의 지반진동 전파특성 및 영향 평가 연구)

  • 최병희;류창하;백승규
    • Explosives and Blasting
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    • v.22 no.1
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    • pp.57-65
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    • 2004
  • Explosive blasting in tunnel excavation produces ground vibration and air blast as its side effects, which may cause complaints from nearby residents. This study was intended to investigate the propagation characteristics of ground vibration induced by tunnel blasting and to evaluate its effects on the residential structures near the site. We have conducted field measurements for 6 blasts and acquired vibration data from 70 measuring points, some of which on positioned inside the tunnel for comparative reason. Various documentation was reviewed to determine an allowable level of peak particle velocity for the residential structures in the area and the allowable limit was set to 0.5 cm/sec. Propagation equations for peak particle velocities were derived from regression analyses using the data acquired at both the surface and the underground tunnel. Finally we proposed appropriate predictive equations for the two areas and a safe blasting criterion.