REPORT ON INVESTIGATION OF SCOUR AT BRIDGES CAUSED BY FLOODS OF 1955

THE DISASTROUS FLOODS IN CONNECTICUT IN AUGUST AND OCTOBER INCURRED LIFE AND PROPERTY LOSSES AMOUNTING TO HUNDREDS OF MILLIONS OF DOLLARS. FOLLOWING THE AUGUST 1955 FLOOD, THREE TEAMS OF FOUNDATIONS ENGINEERS WERE DISPATCHED TO STUDY SCOUR AT THE 75 STATE-OWNED OR STATE-MAINTAINED BRIDGES THAT WERE DAMAGED OR DESTROYED. THEY MADE CAREFUL MEASUREMENTS OF MAXIMUM AND AVERAGE DEPTHS OF SCOUR AND OBTAINED OTHER DATA RELATIVE TO MAXIMUM HIGH WATER, MODE OF FAILURE, DEBRIS, AND CHANNEL CHARACTERISTICS. THE RESULTS OF THESE STUDIES AND THE FACTORS INFLUENCING THE VARIOUS MODES OF FAILURE ARE PRESENTED AND DISCUSSED. AT MANY OF THE BRIDGES STUDIED THE FOUNDATIONS WERE UNHARMED AND THE FAILURES WERE ONLY IN THE PIER OR ABUTMENT WALLS OF SUPERSTRUCTURES. AT OTHER BRIDGES WHERE FAILURE WAS CAUSED BY SCOUR, THAT SCOUR WAS GREATLY INCREASED BY "SECONDARY SCOUR", WHICH OCCURRED AFTER COLLAPSE OF THE STRUCTURE, SO THE ORIGINAL SCOUR PICTURE IS NOT CLEAR. HOWEVER, AT 18 BRIDGES THE ORIGINAL SCOUR COULD BE MEASURED ACCURATELY AND THE MAXIMUM HEIGHT OF WATER WAS KNOWN; DATA FROM THESE 18 BRIDGES WAS CAREFULLY ANALYZED AND A FORMULA WAS FOUND THAT WOULD FIT THESE DATA. THIS FORMULA RELATES THE AVERAGE DEPTH OF SCOUR TO THE DIFFERENCE BETWEEN THE SEDIMENT LOAD IN THE APPROACH FLOW AND THE TRANSPORT CAPACITY UNDER THE BRIDGE. EXAMPLES OF THE APPLICATION OF THE SCOUR FORMULA ARE INCLUDED. /AUTHOR/

  • Supplemental Notes:
    • Vol 27, No 8, PP 14-31, 10 FIG, 1 TAB, 5 REF
  • Authors:
    • Moulton, L K
    • Belcher, C
    • Butler, B E
  • Publication Date: 1957-9

Media Info

Subject/Index Terms

  • TRT Terms: Bridges; Floods; Scour
  • Subject Areas: Bridges and other structures; Highways; Hydraulics and Hydrology;

Filing Info

  • Accession Number: 00204425
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 16 1972 12:00AM