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Investigation and Application of Voussoir Beam Theory for the Stability Evaluation of Underground Excavations

  • Author / Creator
    Hu, Chaoshi
  • Voussoir beam theory, also named as arching action, has been widely accepted and applied in design and construction of both surface and underground structures. This investigation focused on its underground applications with moderately jointed rock, such as underground mining and tunneling. There are discrepancies between the voussoir beam models built by different researchers, for example, the shape and depth of the induced stress at abutment and midspan and the beam shortening equation. In this investigation, the behavior of voussoir beam under transverse loading was investigated through physical, numerical and theoretical modeling. It was found that the stress distributions at the midspan and abutment are different both in shape and depth through the photogrammetric analysis in physical investigation. And the stress distribution is changing as the loading changes. Using the physical tests as calibration and validation, the finite element code, Phase2 8.0, was selected to further the investigation. Systematically numerical modeling was performed to cover the voussoir beams with common ratios of span/thickness encountered in the field. The characteristics of voussoir beam behavior were obtained. An analytical model was built based on a general form of stress distribution at the abutment and midspan with different depths of stress distribution. Based on the findings from physical and numerical investigations, an iteration procedure was proposed to determine the stability and deflection of voussoir beams under transverse loading. The voussoir beam model developed was applied to analyze the mechanical behavior of stress riser of segmental precast concrete liner. The stress distribution at the stress riser of segmental liner cannot be derived from existing closed form solution. There is always the uncertainty about the compressive failure of the segment liner especially when hair cracks happened at stress risers. Through modelling one piece of segment liner as a voussoir beam, the stress distribution and deflection at stress riser were obtained. It shows the stress riser is free from compressive failure for the target project. This is verified in the field by safely removing the temporary “reinforcing” measures. Voussoir beam theory is a suitable analytical method for the design of segmental tunnel liners.

  • Subjects / Keywords
  • Graduation date
    2016-06:Fall 2016
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/R30C4SW1T
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
    English
  • Institution
    University of Alberta
  • Degree level
    Doctoral
  • Department
    • Department of Civil and Environmental Engineering
  • Specialization
    • Mining Engineering
  • Supervisor / co-supervisor and their department(s)
    • Apel, Derek (Civil and Environmental Engineering)
    • Sudak, Les J (Mechanical and Manufacturing, University of Calgary)
  • Examining committee members and their departments
    • Sudak, Les J (Mechanical and Manufacturing, University of Calgary)
    • Apel, Derek (Civil and Environmental Engineering)
    • Dehghanpour, Hassan (Civil and Environmental Engineering)
    • Liu, Wei Victor (Civil and Environmental Engineering)
    • Wong, Ron C (Civil Engineering, University of Calgary)