AN INVESTIGATION OF THE SHAFT AND BASE RESISTANCE OF LARGE BORED PILES IN LONDON CLAY

THIS PAPER PRESENTS THE RESULTS OF LOADING TESTS ON DEEP BORED CYLINDER FOUNDATIONS IN LONDON CLAY IN WHICH LOAD CELLS WERE INSTALLED AT THE BOTTOM OF THE SHAFTS TO MEASURE THE LOADS CARRIED BY THE BASES. SINCE THE LONDON CLAY IS FISSURED THERE IS CONSIDERABLE VARIATION IN THE RESULTS OF STRENGTH TESTS ON BOREHOLE SAMPLES FROM A SITE INVESTIGATION. TESTS SHOW THAT THE FACTORS USED IN A FORMULA FOR ULTIMATE BEARING CAPACITY MUST BE RELATED TO THE MANNER IN WHICH THE STRENGTH VALUES ARE INTERPRETED. AS THE FOUNDATIONS SETTLE, THE SHAFT FRICTION DEVELOPS MORE RAPIDLY THAN THE BEARING RESISTANCE OF THE BASE. SAFETY FACTORS ARE DISCUSSED IN RELATION TO THIS AND A DESIGN METHOD IS PROPOSED FOR THE LIMITATION OF SETTLEMENT BASED ON THE USE OF INTER-RELATED LOAD FACTORS APPLIED TO THE FRICTIONAL AND BASE COMPONENTS OF RESISTANCE. THESE FACTORS ARE DERIVED EMPIRICALLY FROM THE TEST RESULTS. THE WAY IN WHICH THE DRILLING AND CLEANING OF THE FOUNDATIONS BEFORE CONCRETING ARE CARRIED OUT HAS A MAJOR EFFECT ON THE BEHAVIOR OF THE FOUNDATIONS AND THE ANALYSIS HAS BEEN CONFINED TO THOSE SHOWING A CONSISTENT PERFORMANCE. THE INVESTIGATION DOES NOT DEAL WITH FOUNDATIONS IN GROUPS, NOR DOES IT TAKE ACCOUNT OF SETTLEMENT DUE TO CONSOLIDATION. /AUTHOR/

  • Corporate Authors:

    Building Research Station /UK

    /Current Papers, Engineering Series
    ,   USA 
  • Authors:
    • Whitaker, T
    • Cooke, R W
  • Publication Date: 1966-2

Language

  • English

Media Info

  • Pagination: 49 p.
  • Serial:
    • Issue Number: 31

Subject/Index Terms

Filing Info

  • Accession Number: 00231077
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 15 2004 1:40AM