This paper reviews the state of the art and future research in conventional drilling and blasting. Although machine tunneling is relatively new, the drilling and blasting techniques now being used have been practiced for several centuries and it is doubtful whether they will become completely obsolete. Rock that is too hard to cut economically with a machine must be excavated in the conventional manner. Tunneling machines are expensive both to purchase and to install; consequently they are frequently uneconomical in shorter tunnels. As a result of the many improvements in excavating tunnels by drilling and blasting, tunnels are today being driven twice as fast and sometimes with less labor than they were forty years ago. Improvements include the drill jumbo, removable drill bits, better steels, more powerful pneumatic drills, and larger and faster mucking machines. Research in improved drilling and blasting operations include the following areas: Faster drilling, in order to substantially increase the current drilling speed. Automation of drilling mechanisms, to eliminate the delay now caused by human factors. Mechanical loading of explosives, to substantially save in labor cost and loading time. Hydraulic drills and new rock-breaking techniques will possibly eliminate the need for explosives. Smoother excavation will reduce the increased cost for labor and ground supports and to the cost of concrete linings. Faster muck removal could be achieved through education and improved labor-management relations. Finally, measuring surfacing vibrations must be accurately predicted particularly when blasting occurs under densely populated areas.

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    • This article appeared in TRB Special Report No. 171, Tunnel Construction: State of the Art and Research Needs. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Jacobs, J D
  • Publication Date: 1977

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  • Media Type: Print
  • Features: Photos;
  • Pagination: pp 5-6
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Filing Info

  • Accession Number: 00156030
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Oct 13 1977 12:00AM