Site-Specific Framework to Estimate Likelihood of Initiation of Internal Erosion from Historical Performance of Dam Portfolio
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The use of historical performance to estimate future performance of a given structure can be a beneficial approach when well-defined, widely accepted quantitative tools are not available.

An example is the quantification of initiation of internal erosion of embankment dams and their foundations. However, this method has a major shortcoming: data sets with information on past-performance are limited to certain types of dams (e.g., construction materials and methods, drainage system, geologic setting), which can bias the estimation of future performance if the dam in question has different characteristics than those used to compile past-performance data. A framework is available and has been previously used to estimate the frequency of initiation using Bayes' Theorem to determine a posterior (updated) frequency of initiation of internal erosion from a prior frequency of initiation based on historical performance. The analysis begins with the historical frequencies for initiation of internal erosion for a particular portfolio of dams. Elicitation is performed considering site-specific characteristics (e.g., construction features, observed performance) and whether those characteristics would also be observed in the portfolio of dams that experienced initiation of internal erosion or those that did not experience initiation of internal erosion to estimate likelihoods. Bayes' Theorem is applied to the historical annual frequencies for initiation of internal erosion (prior estimate) and the elicited likelihoods to calculate an updated site-specific frequency for initiation of internal erosion (posterior estimate). This paper presents an example application of the framework to estimate the annual likelihood of initiation of internal erosion considering site-specific characteristics and conditions of a fictitious earthen embankment dam.

Publication Summary

  • Geosyntec Authors: Clinton Carlson, Glenn Rix, Lucas de Melo
  • All Authors: Clinton Carlson, Glenn Rix, Lucas de Melo, Marty McCann
  • Title: United States Society on Dams (USSD) 2022 Annual Conference
  • Event or Publication: Event
  • Practice Areas: Dams; Dam Safety
  • Citation: United States Society on Dams (USSD) 2022 Annual Conference and Exhibition at the Town and Country Resort in San Diego, California on April 11 through 14, 2022.
  • Date: Tuesday, April 12 at 11:30 a.m. PDT
  • Location: San Diego, California
  • Publication Type: Platform Presentation