BRIDGE VIBRATIONS - SUMMARY OF QUESTIONNAIRE TO STATE HIGHWAY DEPARTMENTS

A SUMMARY AND DISCUSSION IS PRESENTED OF A TWO-PART QUESTIONNAIRE WHICH WAS DEVELOPED AND CIRCULATED TO ALL STATE HIGHWAY DEPARTMENTS ON BRIDGE VIBRATIONS. OF FORTY-ONE REPLIES RECEIVED ONLY FOURTEEN STATES REPORTED HAVING RECEIVED COMPLAINTS. FOUR OF THESE REPLIES INDICATE ONLY ONE BRIDGE THAT VIBRATES AND TWO OF THESE WERE CORRECTED BY DECK REPAIR. FOUR STATES INDICATE THAT THEY HAVE HAD TWO PROBLEM STRUCTURES IN RECENT HISTORY. THE REMAINING SIX STATES REPORT SIXTY-TWO PROBLEM BRIDGES AND INDICATE MORE ON WHICH THEY HAVE HAD NO FORMAL COMPLAINT. VIBRATION PROBLEMS ARE DISCUSSED AND IT IS SUGGESTED THAT SPECIFICATIONS FOR THE DEFLECTION LIMITATION AND THAT TO SPAN RATIO BRIDGES MIGHT BE ALTERED TO RECLASSIFY BRIDGES IN THREE CATEGORIES WITH THE FOLLOWING RESTRICTIONS: (1) BRIDGES RESTRICTED TO VEHICULAR TRAFFIC SHOULD HAVE STRESS RESTRICTIONS ONLY, (2) BRIDGES IN URBAN AREAS WITH MOVING PEDESTRIAN TRAFFIC AND PARKING SHOULD HAVE A MINIMUM STIFFNESS OF 200 KIPS PER INCH OF DEFLECTION TO PRACTICALLY MINIMIZE THE VIBRATIONS, AND (3) BRIDGES WITH BENCHES, FISHING, OR OTHER LOITERING PEDESTRIAN TRAFFIC SHOULD HAVE A MINIMUM STIFFNESS OF 200 KIPS PER INCH OF DEFLECTION, PLUS DAMPING OF 7.5 PER CENT CRITICAL DAMPING OF THE BRIDGE, TO ELIMINATE VIBRATIONS.

  • Supplemental Notes:
    • No 107, 12 PP, 1 FIG, 9 REF
  • Publication Date: 1970-2

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Filing Info

  • Accession Number: 00209193
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 25 1970 12:00AM