MOLE'S TOUGHEST TEST YET: GRANITE

METHODS FOR MINING GRANITE USING A TUNNELING MACHINE ARE DESCRIBED FOR THE 3 MI. LONG NAST TUNNEL SET HIGH IN THE COLORADO ROCKIES JUST WEST OF THE CONTINENTAL DIVIDE. ALTHOUGH THE HARDNESS OF GRANITE WAS THOUGHT TO BE 25,000 PSI., LATER TESTS REVEALED THAT THE HARDNESS WAS BETWEEN 16,360 AND 33,500 PSI. THE MOLE'S COMPONENTS ARE DISCUSSED IN TERMS OF THE RESTRAINTS THAT WERE IMPOSED UPON THE PROJECT.

  • Supplemental Notes:
    • VOL 47 NO 8 PP 54,59, 62-3
  • Publication Date: 1972-8

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Filing Info

  • Accession Number: 00236418
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 19 1972 12:00AM