TENSION PILE

THE RESULTS OF A SHORT TERM STUDY OF A PILE IN TENSION LOADS ARE REPORTED. THE "TENSION" PILE QUESTION WAS RAISED WHEN A DEPRESSED ROADWAY TO BE BUILT IN THE CITY OF NEW ORELEANS WHERE THE WATER TABLE IS AT OR VERY NEAR THE SURFACE WAS CONCEIVED. PILES WERE TO BE USED TO "HOLD DOWN" THIS EXPRESSWAY. FOUR PILES WERE DRIVEN; THREE WERE USED IN THE STUDY. TWO WERE REACTION PILES, AND ONE WAS THE TEST PILE. IT WAS PLACED IN A TENSION LOAD OF 40 TONS FOR A PERIOD OF SIX MONTHS FORTY TONS WAS APPROXIMATELY ONE WAS THE TEST PILE. IT WAS PLACED IN A TENSION LOAD OF 40 TONS FOR A PERIOD OF SIX MONTHS. FORTY TONS WAS APPROXIMATELY ONE FOURTH OF THE TOTAL BEARING LOAD COMPUTED FROM THE PILE DRIVING FORMULA. THERE WAS NO MOVEMENT. AT THE COMPLETION OF THE SIX MONTHS THE PILE WAS LOADED TO FAILURE IN TENSION. FAILURE PREDICTABLY OCCURRED AT APPROXIMATELY 98 TONS. FOUR CRACKS APPEARED IN THE MEMBER 89 TONS, 90 TONS, 97 TONS, AND 98 TONS. FIVE OF THE EIGHT PRESTRESS CABLES USED TO PLACE THE PILE IN TENSION BROKE. JUST PRIOR TO THIS LATTER EVENT THERE APPEARED TO BE 0.17 INCHES OF MOVEMENT UPWARD, BUT WHEN THE LOAD WAS REMOVED THE PILE RETURNED TO ITS ORIGINAL ELEVATION AND THE CRACKS CLOSED. IT IS CONCLUDED THAT PILES DRIVEN IN STIFF TO VERY STIFF CLAYS AND ALLOWED TO REMAIN UNLOADED FOR SEVERAL MONTHS WILL REACT FAVORABLY IN TENSION. /AUTHOR/

  • Corporate Authors:

    Louisiana Department of Highways

    P.O. Box 44245, Capitol Station
    Baton Rouge, LA  USA  70804

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590
  • Authors:
    • Walters, W C
  • Publication Date: 1970-7

Subject/Index Terms

Filing Info

  • Accession Number: 00230730
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: 68-4st (B)
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Apr 1 1971 12:00AM