A LABORATORY AND PILOT-SCALE STUDY ON THE CUTTING OF CHALK CONTAINING FLINTS

The object of the study described was to determine the ability of drag picks and discs, when mounted on the head of a full-face tunnelling machine, to excavate chalk containing flints. Laboratory cutting tests were carried out with picks and discs using a modified shaping machine in a triaxial dynamometer which measured the three components of cutting force. The picks used for the tests were 50 mm square and had a rake angle of 30 deg and the single disc cutting tests were carried out using 100 mm cutting discs. The drag picks were found unsuitable as they were likely to fracture under shock load while the disc cutters were found suitable for excavating chalk containing flint. The results indicate that no difficulty should be experienced in cutting chalk with flint where full-face tunnelling machines would have ample power and larger discs able to cope with peak normal forces in excess of 50 kn. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/0041414X
• Corporate Authors:

  Morgan-Grampian Limited

  30 Calderwood Street
  London SE18 6QH,   England 
• Authors:
  • CRABB, G I
  • Hignett, H J
• Publication Date: 1980-1-2

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 29-33
• Serial:
  • Tunnels & Tunnelling International
  • Volume: 12
  • Issue Number: 1
  • Publisher: Progressive Media Markets, Ltd
  • ISSN: 0041-414X

Subject/Index Terms

• TRT Terms: Chalks; Construction management; Cutting; Cutting tools; Dynamometers; Excavating equipment; Excavation; Excavations; Flint; Force; Laboratories; Laboratory tests; Loads; Measurement; Sawing; Tests; Triaxial shear tests; Tunneling; Tunneling machines; Tunnels
• Old TRIS Terms: Cutters; Excavation technology
• ITRD Terms: 4120: Chalk; 3666: Construction method; 5155: Excavation (process); 4170: Flint; 6237: Laboratory (not an organization); 5567: Load; 6136: Measurement; 5128: Sawing; 6255: Test; 3374: Tunnel
• Subject Areas: Bridges and other structures; Construction; Highways; I54: Construction of Tunnels;

Filing Info

• Accession Number: 00312098
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jul 22 1980 12:00AM