PARALLELISM OF BORE HOLES: AN ESSENTIAL ELEMENT FOR THE SUCCESS OF PRECUTTING

FAILURES RESULTING FROM BOREHOLES NOT BEING SUFFICIENTLY PARALLEL ARE OFTEN DUE TO WAGON-DRILL- TYPE EQUIPMENT WITH A SINGLE HAMMER, HENCE THE NEED FOR MOVING AND REPOSITIONING THE EQUIPMENT QUITE FREQUENTLY. THERE EXIST, AT THE PESENT TIME, DEVICES SPECIALLY ADAPTED TO PRECUTTING WHICH DO NOT HAVE THESE DRAWBACKS, E. G. THE SPECIAL DRILLING DEVICE USED ON THE A53 MOTORWAY. ITS FRAME, 6M 50 LONG, SUPPORTS TWO HAMMERS WHICH FACILITATE THE DRILLING OF 8 HOLES 80 CM APART, SIMULTANEOUSLY. THE BOREHOLES ARE THEN DRILLED AUTOMATICALLY IN THE SAME PLANE. /LCRC/TRRL/

  • Authors:
    • Gaudin, B
  • Publication Date: 0

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00229422
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: May 15 1973 12:00AM