THERMAL-MECHANICAL FRAGMENTATION OF HARD ROCK FOR RAPID EXCAVATION

This project was initially begun to determine techniques of combining thermal and mechanical methods of excavating hard rock, primarily for tunneling. Investigations to date have shown that rock excavation of tunnel faces with splitters is technically and economically feasible with two improvements: an impact hammer was added to the splitter system, and by using longer wedge and feathers, the speed of fracture was increased and broken fragments were sufficiently displaced so that they were no longer keyed in place and could be easily removed from the face. These concepts have 'opened the door' upon a number of basic research problems which must be solved in order to make the tools of optimum effectiveness for excavation systems. The research problems are amenable to solution.

• Corporate Authors:

  University of Missouri, Rolla

  Rock Mechanics and Explosives Research Center
  Rolla, MO  United States  65409

  National Science Foundation

  Research Applied to National Needs
  Washington, DC  United States  20550
• Authors:
  • Clark, G B
  • Lehnhoff, T F
• Publication Date: 1975-12

Media Info

• Pagination: 113 p.

Subject/Index Terms

• TRT Terms: Excavating equipment; Excavation and tunneling; Excavations; Finite element method; Fracture mechanics; Mechanical properties; Rocks; Splitting (Communications); Thermal properties
• Uncontrolled Terms: Fragmentation
• Old TRIS Terms: Splitting
• Subject Areas: Construction; Geotechnology; Highways;

Filing Info

• Accession Number: 00143156
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: NSF/RA-760017 Ann. Rpt.
• Contract Numbers: NSF-GI-38984
• Files: TRIS
• Created Date: Oct 6 1976 12:00AM