BORING IN SLATE FOR BRIDGE FOUNDATIONS

This article gives a brief account of the problems associated with the bearing piles for the west abutment of Greta bridge at Keswick where five 1.8M diameter shafts were bored through skiddaw slate to depths of up to 13.8M. The shafts were considered necessary to found the abutment on more stable rock, because the slate dipped steeply towards the river. Columns were constructed in the shafts in permanent liners and the gap was filled with free draining material. A pilot hole was first drilled followed by enlargement with an auger. The final holes were drilled using a Hughes CEZ 450 rig mounted on an NCK Atlas crane and NCK Andes service crane. The holes were drilled in 2-3M runs using a core barrel of the full diameter followed by an auger. The dip of the slate beds was sometimes 70 degrees to the horizontal, but no trouble was encountered in boring a straight hole. Several hundred gallons of water per minute were used for flushing purposes, but recycling and small water losses avoided pollution of the salmon and trout river. The whole boring contract was completed in 2 1/2 working weeks. /TRRL/

  • Availability:
  • Corporate Authors:

    Wells (Edward) and Sons, Limited

    143/145 Camberwell New Road
    London SE5,   England 

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Publication Date: 1975-7

Media Info

  • Features: Photos;
  • Pagination: p. 51
  • Serial:
    • GROUND ENGINEERING
    • Volume: 8
    • Issue Number: 4
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00133732
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jun 23 1976 12:00AM