• Title/Summary/Keyword: FFRC method

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Evaluating Shear Wave Velocity of Rock Specimen Through Compressional Wave Velocities Obtained from FFRC and Ultrasonic Velocity Methods (양단자유공진주 및 초음파속도법으로 획득한 압축파 속도를 이용한 암석시편의 전단파 속도 도출)

  • Bang, Eun Seok;Park, Sam Gyu;Kim, Dong Soo
    • Geophysics and Geophysical Exploration
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    • v.16 no.4
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    • pp.250-256
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    • 2013
  • Using shear wave velocity is more reasonable to estimate strength and integrity of rock compared with using compressional wave. It is often ambiguous to pick the dominant frequency caused by torsional wave when evaluating $V_S$ of rock specimen from FFRC method. It is also sometimes ambiguous to pick the first arrival point of S wave compared with P wave in the signals acquired from ultrasonic velocity method. Otherwise, the procedure of evaluating $V_P$ using ultrasonic velocity method and $V_L$ using FFRC method is relatively stable. Through the relationship between elastic modulus, poisson's ratio and $V_S$ can be obtained from $V_P$, $V_L$. Applicability was checked using model specimens having different material property and length and rock specimens sampled in mine area, and usefulness of proposed procedure was verified.