Scour Around Bridge Piers and Abutments

Man’s never-ending search for better materials and construction methods and for techniques of analysis and design has overcome most of the early difficulties of bridge building. Scour of the stream bed, however, has remained a major cause of bridge failures ever since man learned to place piers and abutments in the stream in order to cross wide rivers. Considering the overall complexity of field conditions, it is not surprising that no generally accepted principles (not even rules of thumb) for the prediction of scour around bridge piers and abutments have evolved from field experience alone. The flow of individual streams exhibits a manifold variation, and great disparity exists among different rivers. The alignment, cross section, discharge, and slope of a stream must all be correlated with the scour phenomenon, and this in turn must be correlated with the characteristics of the bed material ranging from clays and fine silts to gravels and boulders. Finally, the effect of the shape of the obstruction itself-the pier or abutment-must be assessed. Since several of these factors are likely to vary with time to some degree, and since the scour phenomenon as well is inherently unsteady, sorting out the influence of each of the various factors is virtually impossible from field evidence alone. The experimental approach was chosen as the investigative method for this study, but with due recognition of the importance of field measurements and with the realization that the results must be interpreted so as to be compatible with the present-day theories of fluid mechanics and sediment transportation. This approach was chosen because, on the one hand, the factors affecting the scour phenomenon can be controlled in the laboratory to an extent that is not possible in the field, and, on the other hand, the model technique can be used to circumvent the present inadequate understanding of the phenomenon of the movement of sediment by flowing water. In order to obtain optimum results from the laboratory study, the program was arranged at the outset to include a related set of variables in each of several phases into which the whole problem was divided. The phases thus selected were : 1. Geometry of piers and abutments, 2. Hydraulics of the stream, 3. Characteristics of the sediment, 4. Geometry of channel shape and alignment.

  • Record URL:
  • Corporate Authors:

    University of Iowa, Iowa City

    Iowa Institute of Hydraulic Research, 300 South Riverside Drive
    Iowa City, IA  United States  52242-1585

    Iowa State Highway Commission

    800 Lincoln Way
    Ames, IA  United States  50010

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590

    Iowa Department of Transportation

    Iowa Highway Research Board, 800 Lincoln Way
    Ames, IA  United States  50010
  • Authors:
    • Laursen, Emmett M
    • Toch, Arthur
  • Publication Date: 1956-5

Language

  • English

Media Info

  • Media Type: Web
  • Features: Figures; Tables;
  • Pagination: 64p

Subject/Index Terms

Filing Info

  • Accession Number: 01050471
  • Record Type: Publication
  • Report/Paper Numbers: Bulletin No. 4
  • Files: TRIS, STATEDOT
  • Created Date: May 23 2007 4:02PM