PERMAFROST TUNNELING BY A CONTINUOUS MECHANICAL METHOD

THE ALKIRK CONTINUOUS CYCLIC MINING METHOD WAS EMPLOYED TO EXCAVATE THE ALASKA EXPERIMENTAL PERMAFROST TUNNEL IN A PERENNIALLY FROZEN STRATUM OF FAIRBANKS SILT AT THE EDGE OF A GOLD DREDGE FIELD 11 MILES NORTH OF FAIRBANKS. THE TUNNEL IS 360 FT LONG AND ABOUT 7 X 13 FT IN CROSS SECTION. CERTAIN PROPERTIES OF THE FROZEN SILT WERE INVESTIGATED, AND THE TUNNEL WAS EVALUATED AS A SHELTER FOR MILITARY PURPOSES. TEMPERATURES, MECHANICAL COMPOSITIONS, AND MOISTURE CONTENTS ARE DISCUSSED, AND OBSERVATIONS ON PLASTIC DEFORMATION ARE GIVEN. THE MACHINE USES A PILOT-PULL PRINCIPLE TO PROVIDE FACE PRESSURE. ITS POTENTIAL PERFORMANCE WAS EVALUATED. SPECIAL OBSERVATIONS OF CUTTING STRAIN AND POWER CONSUMPTION WERE PERFORMED AND THE CUTTING PROCESS WAS ANALYZED. IT WAS FOUND THAT THE MECHANICAL PROCESS IS EXPEDIENT AND THAT WITH MODIFICATIONS THE ALKIRK PRINCIPLE PROMISES TO BECOME A FEASIBLE METHOD OF EXCAVATING DEEP SHELTERS IN PERMAFROST. SUBSURFACE SHELTERS IN PERMAFROST PROVIDE ADVANTAGEOUS PROTECTION AGAINST HIGH VELOCITY SHOCKS. THE OPERATION'S EFFICIENCY IS ANALYZED IN THE APPENDIX. /AUTHOR/

• Supplemental Notes:
  • Tech Rept 221, 37 PP, FIGS 4 TAB, PHOTS, REFS, 1 APP
• Authors:
  • Swinzow, G K
• Publication Date: 1970-11

Media Info

• Serial:
  • CRREL REPORT
  • Publisher: THE LABORATORY

Subject/Index Terms

• TRT Terms: Excavation and tunneling; Permafrost; Shelters; Soil mechanics; Tunneling machines
• Old TRIS Terms: Continuous methods
• Subject Areas: Geotechnology; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 00219417
• Record Type: Publication
• Files: TRIS
• Created Date: May 3 1971 12:00AM