Pipe Networks Risk Assessment Based on Survival Analysis

Abstract

Integrated management of pipe networks should include methods for monitoring, repairing and replacing deteriorating components (usually pipes), but also methods and everyday operating practices towards a proactive risk assessment approach in order to give a solid answer to the unavoidable "repair or replace" dilemma. The present paper attempts to check whether the Discriminant Analysis and Classification (DAC) method can be used to achieve the above mentioned goals and predict the future behaviour of network pipes. Three pipe networks carrying different types of fluids (oil; gas; and water) are used as case studies. For each case study network, the DAC method is used to classify the pipes into two groups (failures/successes), based on simple variables (pipe/network characteristics) and dimensionless joint ones. Several scenarios are being analysed for each case. The results for the two cases of oil and gas networks are very satisfying. The implementation of the DAC method to water pipe networks needs to overcome serious problems related to the quality, reliability and compatibility of the data records provided by the Water Utilities. In this paper, these shortcomings are faced combining field data with theoretical one. Also the distinction between what "failure" and "success" actually mean in a water pipe network has to be determined. The present study uses the total water volume being lost as a definition criterion.

A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

“…The MSRRI combines two univariate indicators: "inflow-demand reliability indicator (IDR)", which considers change of inflow to reservoirs due to climatic and meteorological states, and "water storage resilience indicator (WSR)", which addresses performance of the engineered infrastructure against climatic and hydrological variability. The WSR indicator provides performance information on the sufficiency of the reservoir storage for meeting water demand over the selected time period, as defined in Equation (5).…”

“…The reliability with risk management has been widely used as the primary criterion in engineering and managing water infrastructure systems [1][2][3][4][5][6][7]. Conventional risk-based strategies have been implemented to guide protection and prevention options that seek to mitigate or avoid the likelihood of expected (targeted) disruptive events and the potential adverse impact from the events [8][9][10][11].…”

Validation and Comparison of Different Statistical Models for the Prediction of Water Main Pipe Breaks in a Municipal Network in Québec, Canada

“…Comprehensive reviews of the literature concerning probabilistic models predicting the rate of water main pipe breaks can be found in VILLENEUVE et al (1998), PELLETIER (2000, MAILHOT et al (2000), KAZEMI (1988 and, TSITSIFLI and KANAKOUDIS (2010), TSITSIFLI et al (2011) andXU (1993). VILLENEUVE et al (1998), used survival analysis to model the time elapsed between successive breaks.…”

Monitoring Deterioration in a Catchment’s Sewerage System

“…Tsitsifli et al [7] focused on monitoring sewer pipeline deterioration by estimating the likelihood of the next pipe failure, where water leakage is regarded as one of the failures. Their focus was drinking water where leaks are a loss of a resource.…”