COMMINUTION OF ROCK WITH CONTROLLED STRESS WAVES

THE STUDY WAS INITIATED TO PROVE A PRINCIPLE UPON WHICH TO BASE THE DESIGN OF HARD ROCK TUNNELING MACHINES. THE TECHNIQUE INVOLVES TREPANNING A CORE AND SUBSEQUENT COMMINUTION OF THE CORE BY CONTROLLED STRESS WAVES. TO ACHIEVE THE OBJECTIVE, EXPLORATORY EXPLOSIVE TESTS WERE PERFORMED IN THE LABORATORY ON CYLINDRICAL SPECIMENS CAST FROM HYDROSTONE. INSTRUMENTATION WAS INSTALLED ON SOME OF THE SPECIMENS TO RECORD THE DYNAMIC RADIAL STRAIN RESULTING FROM THE EXPLOSIVE DETONATION. BOTH VISUAL AND STRAIN GAGE DATA SHOWED THAT THE SPECIMENS COULD BE FRACTURED IN THE DESIRED MANNER. THE THICKNESS OF THE SPALLING WAS FOUND TO BE DIRECTLY RELATED TO THE RADIAL STRESS WAVE CHARACTERISTICS. THUS, THE SPALL SIZE SHOULD BE CONTROLLABLE BY CHANGING THE DURATION AND MAGNITUDE OF THE WAVE. /AUTHOR/

• Supplemental Notes:
  • Rept No NCEL-TN-1184
• Corporate Authors:

  Naval Civil Eng Lab, Port Hueneme /US

  ,    
• Authors:
  • Murtha, R N
  • Odello, R J
  • Allgood, J R
• Publication Date: 1971-10

Media Info

• Pagination: 48 p.

Subject/Index Terms

• TRT Terms: Comminution; Detonation; Radials; Rock core; Rock mechanics; Rocks; Spalling; Strain gages; Stresses; Tunneling machines; Waves
• Old TRIS Terms: Radial stress
• Subject Areas: Construction; Geotechnology; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 00215578
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: Tech Note
• Files: TRIS
• Created Date: Jun 12 1973 12:00AM