• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.1
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• pp.21-28
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• 1999

The objective of the study is to develop attenuation equations of the ground motions in the southern part of the Korean peninsula. The earthquake source characteristics and the medium properties were estimated from available instrumental earthquake records and used as input parameters. The peak ground accelerations(PGA) and pseudo-velocity response spectra(PSV) were simulated by the random vibration theory. The attenuation equations for the PGA and PSV were constructed in terms of local magnitudes and hypocentral distances.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.2
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• pp.111-117
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• 2008

The effect of characteristics of ground and circular foundation on the dynamic behavior of the foundation in vertical motion are considered using an approximated analytical solution and a finite element analysis with absorbing (consistent transmitting) boundary. The shear wave velocity of homogeneous ground affects the resonant frequency of the foundation much but has nothing to do with the maximum response amplitude at resonant frequency. The density in this case affects both the resonant frequency and the maximum response. The size and the mass of the circular foundation are related both to the resonant frequency and the maximum response. However, Poisson's ratio has very little effect on dynamic behavior of the foundation. When the ground is not homogeneous but has the layers, different formations of shear wave velocities would also change the maximum response at resonant frequency.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.06a
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• pp.83-116
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• 1993

This article analyzed the dynamic compaction incuced vibration of man made waste landfill. General dynamic properties and compaction-condition-related dynamic properties were analyzed. from the results, it was turned out that the shear modulus G=17496-58320 t/m2, dannpln ratio D=14~58%, dominant frequency f=6-14Hz. Also, it was turned out that the propagation velocitis of low amplitude shear wave and compressive wave were increased as the number of impact increased, the relation between peak particle velocity, and impact distance was wpp=5.08.[D/r E]-1.4, the peak particle velocity was high at the lower part of the waste fill layer and the range of dynamically improved area was about 6-10m.

• Tunnel and Underground Space
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• v.23 no.6
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• pp.521-537
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• 2013

While microseismicity induced by hydraulic stimulation carried out for EGS is useful means in estimating the range of permeability increase, it also affect surface structures and environments. In order to establish a mitigation plan for microseismicity triggered by hydraulic stimulation, we reviewed world-wide guidelines on the impact of ground vibration on the surface structure and human environment by blasting. Case studies from Europe and USA on the microseismicity by hydraulic stimulation are presented and suggestions are made for the guidelines on ground vibration by hydraulic stimulation for the ongoing Pohang EGS project.

• Computational Structural Engineering
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• v.11 no.1
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• pp.58-69
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• 1998

본 기사에서는 진동을 유발하는 기계장치의 지지 형태에 따른 해석 모델링 기법을 소개하는데 중점을 두었다. 다양한 해석 모델등 중 어느 것을 사용할 것인가는 주어진 조건이나 정보, 요구되는 정확도, 효율성 등을 고려하여 설계 엔지니어가 판단하여야 한다. 또한 진동 하중을 받는 구조물에 대한 설계 및 해석을 하기 위해서는 기계장치에 대한 사양 및 요구사항, 지반의 물리적 성질, 외부 환경적 요인 등을 파악하여야 한다. 종합적인 판단하에 구조물을 모델링하여 얻어진 결과들을 가지고 실제 설계 요구 조건과 비교, 검토를 하여야 하며, 이러한 설계 조건들은 다음과 같은 사항들을 포함한다. 1) 지반이나 구조물의 파괴, 과도한 처짐 등에 대한 정적 강도를 검토한다. 2) 진동 응답에 대한 최대 변위, 최대 속도, 최대 가속도를 검토한다. 3) 최대 확대계수, 최대 동적하중 계수, 공명조건, 최대 전달계수 등을 포함한 동적 거동을 검토한다. 4) 실제 구조물에서 일어날 수 있는 모든 모드들에 대한 검토를 한다. 5) 기계, 구조물, 연결부 등에 대한 파괴 가능성을 고려한다. 6) 사람이나 기계장치의 작동 등에 대한 환경적 요구조건의 만족 여부를 검토한다.

• Explosives and Blasting
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• v.30 no.2
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• pp.1-8
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• 2012

The only law related to airblast and ground vibration control in Korea is the Noise and Vibration Control Act enforced by the Ministry of Environment. But this law mainly deals with the annoyance aspects of noises and vibrations in ordinary human life. Hence, the law defines the safety criteria of ground vibration as the vibration level (VL) of dB(V) unit. The ground vibrations produced from blasting, however, have the unique characteristics that can be shown in shock vibrations, and the duration is also very short compared to the vibrations from machinery, tools or facilities. Hence, vibration regulations for blasting operations usually define the safety criterion as the peak particle velocity (PPV) considering the effect of ground vibrations to structural damage. Notwithstanding, there are several attempts that predict VL from PPV or estimate VL based on the scaled distances (SD; in unit of $m/kg^{1/2}$ or $m/kg^{1/3}$) without considering their frequency spectra. It appears that these attempts are conducted mainly for the purpose of satisfying the law in blasting contracts. But, in principle there could no correlation between peaks of velocity and acceleration over entire frequency spectrum. Therefore, such correlations or estimations should be conducted only for the waves with the same or very similar frequency spectra.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.461-468
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• 2001

지진등에 의해 유발된 동 하중에 의한 지반-구조물 계의 응답은 지반-구조물사이의 경계에서의 마찰특성과 미끄러짐에 의해 크게 영향을 받게 된다 본 논문에서는 진동대(Shaking table)를 이용하여 조립토와 건설재료(Steel)의 경계에서 지반으로부터 지중구조물에 전달되는 전단응력 의 전달정도를 파악하기 위한 실험을 실시하였다. 본 실험에서 설정한 미끌어짐속도 범위내에서는 미끄러짐속도 변화에 따른 조립토와 건설재료(Steel)사이의 동마찰계수의 변화가 작다는 사실이 관찰되었다. 그리고 조립토의 평균유효입경의 변화가 동마찰계수에 미치는 영향도 함께 조사되었다. 또한 이 동마찰계수를 같은 조립토에 대한 평면변형률시험을 통해 얻어진 최대내부마찰각으로부터 구한 마찰계수와 비교하여 정량화하였다.

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

• Tunnel and Underground Space
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• v.24 no.1
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• pp.97-109
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• 2014

In order to identify the characteristics of the propagation depending on delay time (20, 25 ms) and priming location (top priming, middle priming, bottom priming), test blasts were carried out a total of 4 times using different spacing, burden, drilling length, charge per delay and was derived the formula to predict blast vibration. This study investigated the characteristics of vibration by analysis of the nomogram and prediction of Peak Particle Velocity (PPV) from delay time and priming location by the formula to predict ground vibration. And it analyzed the trends of vibration increase by standards charge 0.5, 1.6, 5, 15 kg. Standards charge is "Blasting design and construction guidelines to road construction" by the Ministry of Land, Infrastructure and Transport. Depending on the charge in favor of vibration control method is proposed. Thus, when the design was to be used as a variable.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.85-95
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• 2009

In urban areas, blast excavation adjacent to tunnels is carried out frequently. It is generally required to secure static and dynamic stability of nearby tunnel structures for any such activities. Although there is some national guidelines for static safety, there is little guides to risk zoning controling the dynamic behavior of the underground structures. In this study, impacts on the blast-induced vibration are investigated using numerical study. An attempt to define the restricted area of blast adjacent to subway tunnels was also made. Particular concerns were given to tunnel depth and ground types. By carrying out the parametric study on depth and ground patterns, the envelope of blast distance of which dynamic response on the lining is controlled under 1 cm/sec, is established. It is shown that the increase in depth has increased the required safety distance slightly until the distance of 3.5 times of the tunnel diameter. Despite small changes in safety distance, it can be generally said that the effects of depth and stiffness of the ground is not significant in controlling the particle velocity of the tunnel linings.