https://www.dora.lib4ri.ch/eawag/islandora/object/eawag%3A8185/datastream/PDF2/Scheidegger-2015-Statistical_failure_models_for_water-%28accepted_version%29.pdf

Statistical failure models for water distribution pipes – A review from a unified perspective

This paper provides an overview of the work performed in the last 13 years to predict the failure of large-diameter trunk water mains. Large-diameter water mains, defined as water mains with a diameter greater than 500 mm, form the main transmission lines in most water distribution systems. The consequences of their failure can be severe and costly. In order for predictive models to be applicable to large-diameter water mains, all models reviewed are capable of analysing individual pipes or pipe segments and calculate either an absolute probability of failure or the hazard of failure relative to other pipes in the system. These models can be divided into two broad categories: physical and statistical models. This review provides a description and a brief critique for each model presented.

State-of-the-art review of water pipe failure prediction models and applicability to large-diameter mains

New stochastic models for preventive maintenance and maintenance optimization

This material is based upon work supported by the National Science Foundation under Award Numbers SES 1444755 and 1934933. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The authors draw on discussions held during a virtual workshop of the National Science Foundation funded Urban Resilience to Extremes Sustainability Research Network on April 2, 2020. This workshop was attended by UREx researchers and practitioners representing 10 United States and Latin American cities.

/pdf/the-value-of-urban-flood-modeling-2pelim8s42.pdf

The Value of Urban Flood Modeling

New shock models based on the generalized Polya process

Sewer asset management gained momentum and importance in recent years due to economic considerations, since infrastructure maintenance and rehabilitation directly represent major investments. Becau...

https://www.tandfonline.com/doi/pdf/10.1080/1573062X.2020.1713382

Sewer asset management – state of the art and research needs

This paper shows how to construct, within the mathematical framework of counting process theory, a Linear Extension of the Yule Process (LEYP) to model the recurrent failures of pressure pipes in water supply networks. The choice of the counting process framework is motivated by an analysis of the advantages and shortcomings of the modelling approaches proposed in the literature over the last thirty years. The parametric nature of the LEYP model enables the prediction of future failures, accounting for the effect of previous failures, pipe ageing, and explanatory factors, assuming proportional hazards. The counting process is Markovian by definition and shown to follow a negative binomial distribution. This property leads to a useful and simple formula for computing conditional predictions given past observed failures. The likelihood of the parameters with respect to a sequence of observed failures is derived using product-integration. Maximum likelihood estimates of the model parameters can be calculated...

Extending the Yule process to model recurrent pipe failures in water supply networks

This paper aims to enable the relevant use of water main service lifetime and failure data to build a medium or long term infrastructure management plan. Firstly, how to estimate the service lifetime distribution of water mains using observations of decommissioning times which are possibly left-truncated and predominantly right-censored, is shown. Three methods are presented: a non-parametric method another based on the parametric Weibull distribution, and a third based on the parametric Herz distribution. An application with actual data related to grey cast iron water mains of two large French and German water distribution networks illustrates the implementation of the theoretical methods. The paper then investigates the link between failure rate and pipe renewal, and discusses the use of observation-based service time survival functions for infrastructure asset management.

https://casses.irstea.fr/wp-content/uploads/2012/04/LeGatY_KroppI_PoultonM-Lesam2011.pdf

Is the service life of water distribution pipelines linked to their failure rate

The long-term maintenance of infrastructure requires asset management. This latter is defined as a series of actions aimed at the long-term maintenance of the capacity of an infrastructure to provide an efficient service for users, at costs and with impacts that are tolerable for society and the environment. The actions implemented concern notably the inventory of infrastructures, their monitoring, inspection and maintenance, the analysis of their state and performance, their reinforcement, renovation, and the definition of long-term technical-financial policies. This article is structured around four themes based on the authors’ experience faced with an analysis of the perspectives set out in recent articles. For each theme, a state of the art largely based on the literature in the field, as well as emerging and nevertheless pressing needs in terms of knowledge production and tools to support reflection and decision-making are presented: temporal and spatial dimensions of water infrastructure asset management and their consistency; multi-infrastructure management seen from the perspective of physical interdependences and decision-aids; governance, organisations and territories; digital representation of the socio-technical infrastructural system. The analysis is carried out following several disciplines from the engineering and, the human and social sciences. Infrastructure linked to water are studied. 

/pdf/water-infrastructure-asset-management-state-of-the-art-and-37c7f4sy.pdf

Yves Le Gat

Papers

Sewer asset management – state of the art and research needs

Extending the Yule process to model recurrent pipe failures in water supply networks

Is the service life of water distribution pipelines linked to their failure rate

Water infrastructure asset management: state of the art and emerging research themes