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Passive Tomographic Study on Velocity Changes in Underground Mines Using Tabular Mesh Grids



Details

  • Personal Author:
  • Description:
    Double difference tomographic inversion on measurements of travelling time and location are performed to analyze the velocity structure within rock mass in underground mining. Residuals of each iteration are estimated to evaluate the conversion of computation. Average wave propagation velocities in tabular areas are assessed to compare the velocity change affected by mainshocks. It is summarized that velocity increases before mainshocks and then reduces with temporal evolution after them. Possible explanations include static stress buildup that enhances the wave propagation before mainshocks and static stress reduction that weakens the waveform propagation. Additionally, wave propagation is attenuated by the dynamic-shaking induced fractures and ruptures within rock masses. Velocity change is shown to be of importance in assessing the stress redistribution and stability of rock masses. It is found that P-wave velocity increased by 1% -approx. 5% before the occurrence of mainshocks. After the mainshocks, the velocity turned into decreasing and eventually dropped to a level that was even lower than the average level before the mainshocks. It can be inferred that stress increased and formed a stress concentration region before the mainshocks. The occurrence of mainshocks caused damage and stress relaxation in the rock mass, leading to a significant velocity decrease. [Description provided by NIOSH]
  • Subjects:
  • Keywords:
  • ISSN:
    1941-8264
  • Document Type:
    Text
  • Funding:
    Contract
  • Genre:
    Journal Article
  • Place as Subject:
  • CIO:
    National Institute for Occupational Safety and Health (NIOSH)
  • Topic:
    Workplace Safety & Health
  • Location:
    North America
  • Volume:
    2022
  • NIOSHTIC Number:
    nn:20067838
  • Citation:
    Lithosphere 2022 Aug; 2022(Special 11):4061650
  • Contact Point Address:
    Tao Yang, North China Institute of Science and Technology, Hebei 06521, China
  • Email:
    yangtao585@163.com
  • Federal Fiscal Year:
    2022
  • Performing Organization:
    Virginia Polytechnic Institute & State University
  • Peer Reviewed:
    True
  • Start Date:
    20110816
  • Source Full Name:
    Lithosphere
  • End Date:
    20160815
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:eff08731ff79e7dd878b1d5d3923938826e1ca60eb20244eda87546005fec8abacc717e161493fcd7d35f1106fb5d1d6dfdcae552f6e57829b5c624e57f519ec
  • Download URL:
  • File Type:
    Filetype[PDF - 860.88 KB ]
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