Methodology for Risk Analysis of Dam Gates and Associated Operating Equipment Using Fault Tree Analysis

Abstract

ABSTRACT:With limited maintenance dedicated to aging dam spillway gate structures, there is an increased risk of gate inoperability and corresponding dam failure due to malfunction or inadequate design. This report summarizes research on methodologies to assist in quantifying risks related to dam gates and associated operating equipment, and how those risks relate to overall spillway failure risk. The objective of the research was to demonstrate how fault tree analytical methods may be applied to improve the quality of dam gate risk analysis.Two different methods of prescreening analysis are presented and evaluated. The first uses probabilities for more events, defined more precisely than in standard practice, and adds criticality ranking; the second uses more traditional estimation of failure probabilities in conjunction with subsystem importance-ranking factors to estimate overall gate system failure probability. Both methods can be linked qualitatively with the Lafitte risk method through event costs and consequences to determine the overall risk for a dam spillway system.

Improved Reliability Models for Mechanical and Electrical Components at Navigation Lock and Dam and Flood Risk Management Facilities

“…Weibull models are recommended for use with fault tree methods for analysis of ME system reliability (Patev, Putcha, and Foltz 2005). Tables 9 and 10 summarize all the median elicitation values for the mechanical system and electrical system at navigation projects.…”

“…These elicited values for CL will be the basis for failure rates to be used with the existing methods for ME system reliability calculations. Additional work on fault trees for ME systems (Patev, Putcha, and Foltz 2005) is being completed as part of dam safety and levee risk assessment procedures development.…”

Sustainment management system dams inspection module : Department of Defense dams inventory and inspection template

“…These efforts did not immediately result in a risk-based approach to dam safety within USACE, but they changed how USACE considered risk. For example, one effort within RADS (Patev et al 2005) looked at using fault tree analysis for evaluating risks associated with dam gates and their operating equipment. RMC and asset management efforts discussed in subsequent sections also look to fault trees to help assess risks and repair priorities for dam components.…”

Using support vector machines to predict the probability of pavement failure

“…The success of a particular modelling technique depends greatly on the appropriateness of the model for the situation at hand and its performance can be enhanced by understanding the underlying causes of failure (Isa et al, 2005). Two such widely employed techniques are failure mode and effect analysis (FMEA) and fault tree analysis (FTA) (Patev et al, 2005;Seyed-Hosseini et al, 2006). FMEA is an analytical tool for reliability analysis that can be used to identify possible failure causes in order to minimise, or eliminate, failure in systems.…”

“…By using a weighted ranking system, each failure is assigned a risk number that represents the overall impact of failure. The causes of failure can be graphically represented using FTA, which further enables concurrently occurring failure factors to be included in the modelling process (Patev et al, 2005). With this approach, the failure paths can be established from the breakdown of the critical paths.…”