DEVELOPMENT OF DESIGN PROCEDURES FOR STABILIZED SOIL SYSTEMS FOR SOFT GROUND TUNNELING: ANALYSIS OF PERFORMANCE AND DESIGN METHOD. VOLUME III

This report is the third in a series of publications covering the results of a research program into the development of a rational design methodology for choosing properties of chemically stabilized soil zones around tunnel openings so as to minimize movements in the surrounding soil. Details are presented concerning: (1) Development of finite element codes for analysis of the stabilized soil tunnel; (2) Studies of the mechanisms for behavior of stabilized soil tunnels; (3) Analysis and evaluation of the first fully documented case history where injection stabilization was used; and (4) Formulation of a simplified and easy-to-use design procedure. Utilizing the finite element codes, the stabilized zone around a tunnel is shown to protect the unstabilized soil by minimizing stress changes beyond the stabilized regions. Stresses are concentrated into the stiff soil zone created by grouting which surrounds the tunnel and it acts as a compression ring during the opening of the tunnel. Discontinuous or partial grout zones around the tunnel are found to not be as effective as continuous zones since their structural action is not as complete. This is confirmed by the case history study. The simplified design procedure is developed to allow for a rational selection of stabilized zone sizes and properties. At this time, it is only applicable to homogeneous soil conditions. It can and will be extended to nonhomogeneous soil profiles. The method allows a designer to select grout zone geometry and properties based upon the maximum settlement considered allowable at the ground surface directly above the tunnel. Charts are provided so that trade-off analyses can be easily made.

  • Supplemental Notes:
    • See also Volume 1, PB-272 771.
  • Corporate Authors:

    Stanford University

    Department of Civil Engineering
    Stanford, CA  United States  94305

    Department of Transportation

    Office of University Research, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Tan, D Y
    • Clough, G W
  • Publication Date: 1979-12

Media Info

  • Pagination: 194 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00313642
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: DOT/RSPA/DPB/50-7926Final Rpt.
  • Contract Numbers: DOT-OS-50123
  • Files: NTIS, TRIS, USDOT
  • Created Date: Jun 26 1980 12:00AM