This report presents the results of model tests on thin shotcrete layers similar to those potentially used as initial tunnel support in flat roofed tunnels. The structural behavior and maximum carrying capacity of these layers were determined in this testing program. The large-scale test facility used in previous work was modified to simulate a flat roofed tunnel. Preliminary tests, using thin mortar layers, were conducted in order to assess the performance of the test device and to evaluate the principal variables controlling the capacity of a thin lining. Results obtained from these tests were used in the planning and evaluation of the shotcrete test program. Three principal modes of failure were observed: diagonal tension in the shotcrete, separation of the layer from the wall, and thrust-moment interaction in the separated portion of the layer. The failure mode was governed mainly by the thickness and boundary conditions of the layer, as well as the adhesive characteristics along the shotcrete wall contact. Other parameters, such as the strength of the shotcrete also affected the maximum carrying capacity of the layers. A conceptual model has been developed to be used as a theoretical framework in the analysis of these and future tests results. Recommendations for future studies of thin shotcrete linings are also given in this report.

  • Corporate Authors:

    University of Illinois, Urbana-Champaign

    Department of Civil and Environmental Engineering
    205 North Mathews Avenue
    Urbana, IL  United States  61801-2352

    Department of Transportation

    Office of Research and Development, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    Federal Railroad Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Fernandez-Delgado, G
    • Mahar, J
    • Cording, E J
    • Parker, H
  • Publication Date: 1976-8

Media Info

  • Pagination: 182 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00158948
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: DOT/TST-76T-19 Final Rpt., UILU-ENG-76-2029
  • Contract Numbers: DOT-FR-30022
  • Files: NTIS, TRIS, USDOT
  • Created Date: Aug 4 1977 12:00AM