THREE-SPAN CONTINUOUS PRESTRESSED CONCRETE BRIDGE CONSTRUCTED OF PRECAST UNITS IN CANTILEVER CONSTRUCTION

DETAILS ARE GIVEN OF THE BRIDGE ACROSS THE TAF FAWR VALLEY IN WALES. THE BRIDGE IS A BOX GIRDER WITH THREE COMPARTMENTS, THE DEPTH VARYING PARABOLICALLY FROM 15 FT AT THE PIERS TO 5 FT AT MIDSPAN AND ABUTMENTS. THE WEBS WERE PRECAST AS I-SECTIONS, AND THE BRIDGE WAS CONSTRUCTED BY CANTILEVERING FROM THE TWO PIERS TOWARD THE ABUTMENTS AND THE CENTER OF THE MAIN SPAN. DURING CONSTRUCTION, THE BRIDGE PASSED THROUGH THREE DIFFERENT STATICAL PHASES: (1) SIMPLY SUPPORTED UNTIL THE CANTILEVERING REACHES THE ABUTMENTS, (2) TWO-PIN PORTAL WHEN RESTING ON ABUTMENTS BUT STILL FREE AT MID-SPAN, AND (3) THREE-SPAN CONTINUOUS WHEN JOINED IN THE MIDDLE. TWO ELECTRONIC COMPUTER PROGRAMS WERE DEVISED. THE FIRST DEALT WITH THE SIMPLY SUPPORTED CONDITION AND GAVE STEP-BY-STEP STRESSES AND DEFORMATIONS AT ALL CONSTRUCTION JOINTS AS THE BRIDGE WAS BEING CONSTRUCTED AND THE PRESTRESSING FORCES WERE INTRODUCED. THE SECOND PROGRAM DEALT WITH THE INDETERMINATE STAGES AND, TO MAKE IT AS GENERAL AS POSSIBLE, WAS DESIGNED ONLY TO GIVE THE CONTRIBUTIONS TO THE COEFFICIENT MATRIX FROM BEAMS WITH VARIABLE CROSS-SECTION, THE VARIATION BEING COMPLETELY ARBITRARY AND THE BEAMS WITH OR WITHOUT END-FIXITY. /RRL/

  • Supplemental Notes:
    • No 23, pp 665-680, 7 FIG, 4 TAB, 4 PHOT
  • Corporate Authors:

    Intl Symp Concr Bridge Des Proc /Can

    ,    
  • Authors:
    • Lundgren, A
    • Hansen, F
  • Publication Date: 1969

Subject/Index Terms

Filing Info

  • Accession Number: 00215057
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Nov 18 1970 12:00AM