Journal of the Korean Society of Mineral and Energy Resources Engineers (한국자원공학회지)

The Korean Society of Mineral and Energy Resources Engineers (한국자원공학회)
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Characteristics of Rock Samples from Seokmo Island Using an Automated-continuous Seismic Velocity Measuring System

자동.연속 측정장치를 이용한 석모도 지표 암석의 탄성파 속도 특성 분석

  • Lee, Sang-Kyu (Korea Institute of Geoscience and Mineral Resources (KIGAM)) ;
  • Lee, Tae-Jong (Korea Institute of Geoscience and Mineral Resources (KIGAM)) ;
  • Sung, Nak-Hoon (Korea Institute of Geoscience and Mineral Resources (KIGAM))
  • Received : 2010.08.02
  • Accepted : 2010.10.04
  • Published : 2010.10.31
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Abstract

Continuous measurements of seismic velocity for the rock samples from Seokmo Island has been carried out. The designed system can measure the seismic velocity of rock samples automatically and continuously. It shows very good accuracy and enables us to study the velocity variations due to temporal changes in degree of saturation and temperature. Saturation of the rock samples causes general increase of P-wave velocity and a relatively small change in S-wave velocity, and the saturation effect shows exponential decrease with respect to porosity increase. Though higher density generally shows higher velocity, the correlation is very weak. Velocity, thermal conductivity, and quartz contents showed close linear relationship as expected. High temperature generally causes the velocity decrease, but some of the rock samples containing microcline shows velocity increase.

석모도 암석시료에 대하여 탄성파속도를 측정하고 그 특성을 분석하였다. 고안된 탄성파 속도 모니터 링 시스템은 자동 연속측정과 정확한 속도측정이 가능하고, 이를 이용함으로써 함수율의 변화, 온도의 변화에 따른 탄성파 속도의 변화에 대한 고찰이 가능하였다. 암석이 포화됨에 따라 일반적으로 P파 속도는 증가하였으며 S파 속도의 경우는 그 변화가 상대적으로 작았다. 또한 포화에 따른 탄성파속도의 변화는 공극률에 반비례하여 공극률이 클수록 그 변화량은 지수함수적으로 감소하여 나타났다. 밀도는 대체로 탄성파속도에 비례하여 나타났으나 그 상관도는 낮다. 열전도도와 석영함량 그리고 탄성파 속도는 예상할 수 있듯이 서로 비례하는 관계를 보인다. 고온은 주로 탄성파속도의 감소를 야기하지만 몇몇 미사장석(microcline)을 함유한 암석의 경우 속도의 증가로 나타났다.

Keywords

Acknowledgement

Supported by : 한국지질자원연구원

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