MODEL TESTS OF LINED TUNNELS IN A JOINTED ROCK MASS

MODEL LAWS GOVERNING THE DESIGN OF GEOMECHANICAL MODEL STUDIES OF UNDERGROUND OPENINGS IN ROCK SUBJECTED TO STATIC LOADS ARE DEVELOPED USING DIMENSIONAL ANALYSIS AND THEORY OF MODELS. THE SIGNIFICANT VARIABLES INFLUENCING THE BEHAVIOR OF ROCK CONSIDERED IN THIS STUDY ARE THE FREEFIELD STRESSES, THE PROPERTIES OF THE DISCONTINUITIES IN THE ROCK MASS, THE OPENING GEOMETRY, AND THE STRUCTURAL LINER SUPPORTING THE OPENING. THE PROTOTYPE CHOSEN FOR STUDY IS A SHORT SECTION OF A LONG CIRCULAR TUNNEL WHICH IS UNDERGROUND AT A DEPTH OF MORE THAN FOUR TUNNEL DIAMETERS. THE DEVELOPMENT OF GEOMECHANICAL MODELING TECHNIQUES FOR THE CONSTRUCTION AND TESTING OF JOINTED ROCK MODELS IS DESCRIBED. THE STRENGTH PROPERTIES OF THE INTACT MODEL MATERIAL AND OF THE JOINT SURFACES ARE ALSO PRESENTED. THE MODELS WERE TESTED IN PLANE STRAIN (ZERO STRAIN PARALLEL TO THE TUNNEL AXIS) BY THE USER OF CONTROLLED RIGID LONGITUDINAL HEAD. FIVE JOINTED MODELS WERE TESTED TO DETERMINE THE EFFECT OF TUNNEL LINER STIFFNESS AND THE RATIO OF JOINT SPACING TO TUNNEL DIAMETER ON THE BEHAVIOR OF TUNNEL LINERS IN JOINTED ROCK MASSES. THE OBSERVED MODEL BEHAVIOR WAS ANALYZED AND COMPARED TO A PREVIOUSLY DEVELOPED ELASTO-PLASTIC ANALYSIS. THE ANALYSES SHOWED THAT ELASTIC THEORY WAS SUFFICIENTLY ACCURATE FOR CALCULATING THE DIAMETRICAL STRAINS OF THE LINED TUNNELS UP TO DIAMETRICAL STRAINS OF ABOUT 1.2%. FOR DIAMETRICAL STRAINS ABOVE 1.2%, THE ELASTO-PLASTIC THEORY WAS USED SUCCESSFULLY TO CALCULATE THE TUNNEL DIAMETRICAL STRAINS WITHIN AN ERROR OF ABOUT PLUS OR MINUS 15%.

  • Supplemental Notes:
    • 2 APP
  • Corporate Authors:

    Construction Engineering Research Laboratory

    Army Corps of Engineers, P.O. Box 4005
    Champaign, IL  United States  61820
  • Authors:
    • HENDRON, A J
    • Engeling, P
  • Publication Date: 1973-5

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 67 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00236669
  • Record Type: Publication
  • Report/Paper Numbers: Tech Rept
  • Files: TRIS
  • Created Date: Feb 12 1974 12:00AM