Accession Number : ADP002387

Title :   Probabilistic Design of Flood Levees,


Personal Author(s) : Grivas,D. A.

Report Date : SEP 1983

Pagination or Media Count : 33

Abstract : A probabilistic procedure is presented that can be used for the design of new flood levees as well as the assessment of the safety of levee systems that are already in operation. The various steps involved in the procedure are briefly outlined, with emphasis placed in the identification and description of possible failure modes, and the determination of the corresponding values of the probability of failure. The latter is achieved with the aid of an approximate method based on point estimates of the statistical moments of the levee failure functions (safety margins). The developed procedure is illustrated in two examples and the obtained results are presented and discussed. Example I involves the determination of the probability of failure of a given levee in slope (both upstream and downstream) sliding and piping. The likelihood for the occurrence of the latter is found under the assumption that the levee material is strong enough to allow the mechanism of piping (roofing) to develop. Example II involves the selection of a levee cross-section and type of fill for a desired value of the probability of failure (P sub f), and the determination of the corresponding value of the conventional factor of safety (FS). This is achieved by developing a relationship (in the form of nomographs) between P sub f and FS for a range of values for the levee geometry.

Descriptors :   *Levees, Embankments, Soil mechanics, Soils, Failure(Mechanics), Sliding, Mathematical analysis, Probability, Symposia

Distribution Statement : APPROVED FOR PUBLIC RELEASE