The application of the rock-melting concept to large, continuous tunneling machines has been studied. System objectives and requirements for an innovative excavation system have been outlined along with a group of particularly costly and perplexing problem areas in conventional tunneling technology which appear to be amenable to solution by the rock-melting concept. Specific data on the established performance of conventional tunnel-boring machines are presented, particularly with regard to advance rate, cutter performance, power consumption, and overall system behavior. Difficulties currently encountered in tunneling in either loose unconsolidated ground or hard abrasive rock are indicated along with representative cost data. Various penetration modes included in the rock-melting concept are described, and associated power-source requirements are discussed. The technique of kerf melting is analytically treated, and conceptual melting-face configurations for a soft-ground and hard-rock-melting tunneler are presented. The utilization of a compact heat-pipe-cooled nuclear reactor to supply the energy for a large-diameter melting tunneler advancing at a high rate is discussed. The unique advantages of high-temperature heat pipes delivering high energy densities to the penetrator melting face are indicated. The utilization of rock-melt debris to form a structural glass tunnel lining and fluidized pipeline material removal techniques are discussed for a well-matched continuous tunneling machine. /Author/

  • Supplemental Notes:
    • Sponsored in part by the National Science Foundation and the U.S. Atomic Energy Commission.
  • Corporate Authors:

    Los Alamos National Laboratory

    P.O. Box 1663
    Los Alamos, NM  United States  87545
  • Authors:
    • Hanold, R J
  • Publication Date: 1973-2

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 35 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00126357
  • Record Type: Publication
  • Report/Paper Numbers: LA-5210-ms
  • Contract Numbers: W-7405-ENG.36
  • Files: TRIS
  • Created Date: Apr 21 1976 12:00AM