ON THE INFLUENCE OF GEOLOGICAL CONDITIONS AT THE APPLICATION OF TUNNEL BORING MACHINES

The geology of two mechanically bored tunnels in Switzerland has been examined in detail. The "boreability" (rate of penetration of the machine) of micaschists, phyllonites, amphibolites and dacites in the sewer and cable tunnel near Lugano (Crespers-Gemmo) was high, because the rock was highly fissured and not affected by alpine metamorphism. In the ventilation shaft of motto di dentro (St. Gotthard highway tunnel) the alpine metamorphic hornblende schists and amphibolites showed very low penetration rates. A high content of fissile minerals leads to high penetration rates. Texture and structure of the rocks and the orientation of the foliation (tunnel axis parallel to the foliation is the most unfavorable case) proved to have an important influence on the penetration rates. (A). /TRRL/

  • Corporate Authors:

    International Association of Engineering Geology

    De-Greift-strasse 195; P.O.B. 1080
    D 415 Krefeld 1,   Germany 

    International Association of Engineering Geology

    De-Greift-strasse 195; P.O.B. 1080
    D 415 Krefeld 1,   Germany 
  • Authors:
    • Wanner, H
  • Publication Date: 1975

Media Info

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Filing Info

  • Accession Number: 00138957
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Nov 17 1976 12:00AM