A simple first order uncertainity analysis is described to demonstrate how uncertainity in the factors which contribute to safety in an embankment influence the uncertainity of the factor of safety. In determining the best estimate of the factor of safety, the best estimates of all factors contributing to resistance and loading should be used. The reliability index is shown to be a measure of safety. Relatively mild assumptions about probability distribution of the factor of safety or movements will provide a useful means of evaluating the relative benefit of spending maney to reduce uncertainity and choosing an economically optimum factor of safety. An example of an expected cost analysis on a sand embankment used for fluid retention is illustrated, and the analysis is described of a highway embankment failure. Since construction and maintenance costs may be closely related to the factor of safety, the cost implications should be considered when a design factor of safety is chosen. One way of reflecting the cost, which must also include the consequences of failure, i.e. maintenance, reconstruction etc., is to evaluate a relative probability failure. The probability of failure multiplied by the cost of failure when added to initial costs gives an expected cost which reflects the trade off between initial cost and suitable risk.

  • Supplemental Notes:
    • Proceedings of the Ohio River Valley Soils seminar held October 5, 1973. This conference was sponsored by the Kentucky Soil Mechanics and Foundations Group of the American Society of Civil Engineers.
  • Corporate Authors:

    American Society of Civil Engineers

    345 East 47th Street
    New York, NY  United States  10017-2398
  • Authors:
    • Baker, W J
  • Publication Date: 1974-12

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 10 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00097156
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 10 1975 12:00AM