Temporal changes in broad-band wave attenuation and velocity of fracturing rock samples

2008 Fiscal Year Final Research Report

• Project/Area Number: 19740280
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Solid earth and planetary physics
• Research Institution: Ritsumeikan University
• Principal Investigator: KAWAKATA Hironori Ritsumeikan University, 理工学部, 准教授 (80346056)
• Project Period (FY): 2007 – 2008
• Keywords: アコースティック=エミッション / 弾性波速度 / 弾性波減衰 / 岩石破壊試験 / 広帯域計測

Research Abstract

岩石試料を用いた三軸圧縮破壊試験において,広帯域弾性波測定用センサーを用いて,破壊の成長にともなう弾性波伝播特性の変化についてしらべた.破壊の進展につれて,圧縮軸方向に透過するP波の速度は緩やかに低下し続け,振幅のみが急激に低下することが明らかにされた.本研究にて初めて実現された周波数解析からは,比較的高い周波数帯と低い周波数帯でのみ振幅の減少が認められたが,速度の逆数に相当する遅れ時間は徐々に増大するものの顕著な周波数依存性は認められなかった.

Research Products

• [Journal Article] Broadband P waves transmitting through fracturing Westerly granite before and after the peak stress under a triaxial compressive condition,
  • Author(s): N. Yoshimitsu, H. Kawakata, N. Takahashi
  • Journal Title: Earth Planets and Space (掲載決定)
  • Peer Reviewed
• [Presentation] A new system of broad-band elastic wave measurement in laboratory under triaxial compressive conditions (2009)
  • Author(s): H. Kawakata, N. Takahashi, N. Yoshimitsu, M. Takahashi
  • Organizer: IASPEI 2009 Meeting
  • Place of Presentation: Cape Town, South Africa
  • Year and Date: 2009-01-14
• [Presentation] Frequency dependent change in amplitude of elastic wave transmitting through fracturing Westerly granite (2008)
  • Author(s): N. Yoshimitsu, H. Kawakata, N. Takahashi,
  • Organizer: 7th ASC General Assembly and SSJ 2008 Fall Meeting
  • Place of Presentation: Ibaraki, Japan
  • Year and Date: 2008-11-26
• [Presentation] Fault structure in Westerly granite samples extracted using a micro-focus X-ray CT scanning system (2008)
  • Author(s): T. Okuno, H. Kawakata, N. Takahashi, M.
  • Organizer: 7th ASC General Assembly and SSJ 2008 Fall Meeting
  • Place of Presentation: Ibaraki, Japan
  • Year and Date: 2008-11-26
• [Presentation] 広帯域センサーを用いた岩石の破壊成長にともなう弾性波速度の変化 (2008)
  • Author(s): 川方裕則, 高橋直樹, 吉光奈奈
  • Organizer: 地球惑星科学連合大会
  • Place of Presentation: 千葉
  • Year and Date: 2008-05-25
• [Presentation] 岩石破壊時における透過P波のコヒーレンスと位相の時間変 (2008)
  • Author(s): 吉光奈奈, 川方裕則, 高橋直樹
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉
  • Year and Date: 2008-05-18