scholarly journals Factors contributing to the failure of asbestos cement water mains

2007 ◽  
Vol 34 (5) ◽  
pp. 608-621 ◽  
Author(s):  
Y Hu ◽  
D W Hubble
Keyword(s):  
Water Distribution ◽  
Structural Integrity ◽  
Clay Soil ◽  
Distribution Networks ◽  
Soil Conditions ◽  
Clear Understanding ◽  
Pipe Failure ◽  
Asbestos Cement ◽  
Water Mains ◽  
The City

Asbestos cement (AC) water mains were installed extensively in North America, Europe, and Australia from the late 1920s to the early 1980s and still form a significant component of water distribution networks of many cities. These water mains are ageing and some water systems have experienced a high breakage rate in AC mains in recent years. It is essential that a clear understanding be developed of the factors contributing to their failure to ensure that municipalities and water authorities can manage their AC water-main assets. In this paper, the historical failure data of AC water mains from the City of Regina were collected and correlated with their corresponding environmental setting, including soil type, water quality, climate, and construction and maintenance practices. The predominant factors that influence the AC pipe breaks were identified. It was observed that pipe age, diameter, climate, clay soil, and construction and maintenance methods all influence the failure of AC water mains in the city, with climate and clay soil conditions being the two critical factors. Some chemical attack from the conveyed water and soil pore water may have occurred and detrimentally affected the structural integrity of the AC water mains. Key words: asbestos cement pipes, water mains, pipe failure, clay soil, climate.

An analysis of pipe breakage in urban water distribution networks

1985 ◽  
Vol 12 (2) ◽  
pp. 286-293 ◽  
Author(s):  
A. J. Kettler ◽  
I. C. Goulter
Keyword(s):  
Cast Iron ◽  
Water Distribution ◽  
Distribution Networks ◽  
Failure Rates ◽  
Pipe Failure ◽  
Modes Of Failure ◽  
Asbestos Cement ◽  
Pipe Systems ◽  
Pipe Breakage ◽  
Joint Regression Analysis

The rates of pipe breakage with increasing pipe diameter and times are investigated. Failure rates for cast-iron pipe are found to decrease with increasing diameter. Changes in pipe failure rates for the various modes of failures are examined in detail. Asbestos-cement and cast-iron pipe overall failure rates are found to increase with time, but for different reasons. Analysis of the modes of failure shows that joint failure is predominant for cast-iron pipe systems with bolted and universal joints whereas the predominant mode of failure for asbestos-cement pipe systems is circumferential cracking. Key words: asbestos cement, cast iron, cracking, diameter, failure rate, joint, regression analysis.

scholarly journals Management of Water Distribution Systems in PDA Condition with Isolation Valves

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 672 ◽  
Author(s):  
Attilio Fiorini Morosini ◽  
Olga Caruso ◽  
Paolo Veltri
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Networks ◽  
Optimal Number ◽  
System Control ◽  
Pipe Failure ◽  
Reliable System ◽  
Network Nodes ◽  
Pipe Burst

The correct management of Water Distribution Networks (WDNs) allows to obtain a reliable system. When a pipe failure occurs in a network and it is necessary to isolate a zone, it is possible that some nodes do not guarantee service for the users due to inadequate heads. In these conditions a Pressure Driven Analysis (PDA) is the correct approach to evaluate network behavior. This analysis is more appropriate than the Demand Driven Analysis (DDA) because it is known that the effective delivered flow at each node is influenced by the pressure value. In this case, it is important to identify a subset of isolation valves to limit disrupting services in the network. For a real network, additional valves must be added to existing ones. In this paper a new methodological analysis is proposed: it defines an objective function (OF) to provide a measure of the system correct functioning. The network analysis using the OF helps to choose the optimal number of additional valves to obtain an adequate system control. In emergency conditions, the OF takes into account the new network topology obtained excluding the zone where the broken pipe is located. OF values depend on the demand deficit caused by the head decrement in the network nodes for each pipe burst considered. The results obtained for a case study confirm the efficiency of the methodology.

scholarly journals Prediction of pipe failure rate in Tehran water distribution networks by applying regression models

2018 ◽  
Vol 19 (3) ◽  
pp. 695-702 ◽  
Author(s):  
Homayoun Motiee ◽  
Sonya Ghasemnejad
Keyword(s):  
Logistic Regression ◽  
Statistical Models ◽  
Poisson Regression ◽  
Regression Models ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Hydraulic Pressure ◽  
Pipe Failure ◽  
Exponential Regression

Abstract Four statistical models (linear regression, exponential regression, Poisson regression and logistic regression) applied to analyze the variables in pipe vulnerabilities with the objective of finding equations to predict probable future pipe accidents. The most effective variables in pipe failures are material, age, length, diameter and hydraulic pressure. To evaluate these models, the data collected in recent years in the water distribution network of district 1 in Tehran were used, with a total length of 582,702 m of pipes, and 48,500 consumers. The results demonstrate that among the four studied models, the logistic regression model is best able to give a good performance and is capable of predicting future accidents with a higher probability.

Spatial and temporal groupings of water main pipe breakage in Winnipeg

1988 ◽  
Vol 15 (1) ◽  
pp. 91-97 ◽  
Author(s):  
I. C. Goulter ◽  
A. Kazemi
Keyword(s):  
Water Distribution ◽  
Interval Parameter ◽  
Pipe Failure ◽  
Spatial And Temporal Patterns ◽  
Exponential Decrease ◽  
Spatial Interval ◽  
Ground Conditions ◽  
Temporal And Spatial ◽  
Pipe Breakage ◽  
The City

The spatial and temporal patterns of water distribution pipe failure in the City of Winnipeg are examined. The failures are shown to be strongly clustered in space, where 22% of the total failures examined occur within 1 m of another failure and 46% occur within 20 m of another failure. A strong temporal clustering is also apparent, with 42% of all failures that occur within 1 m of another found also to occur within 1 day of the initial failure in the group. An exponential decrease in the marginal rates of failure with respect to both the temporal and spatial interval parameter is also observed. Earlier failures in a particular location appear to be an important key to assessing potential failures in that vicinity. These results suggest that a fruitful area for further examination for the reduction of failure rates is the change in the ground conditions resulting from an initial leak and its subsequent repair. Key words: failures, groupings, marginal rates, pipes, space, time, water distribution, Winnipeg.

scholarly journals Complex network and fractal theory for the assessment of water distribution network resilience to pipe failures

2017 ◽  
Vol 18 (3) ◽  
pp. 767-777 ◽  
Author(s):  
Armando Di Nardo ◽  
Michele Di Natale ◽  
Carlo Giudicianni ◽  
Roberto Greco ◽  
Giovanni Francesco Santonastaso
Keyword(s):  
Complex Network ◽  
Water Distribution ◽  
Fractal Theory ◽  
Distribution Networks ◽  
Pipe Failure ◽  
Operational Conditions ◽  
Complex Network Theory ◽  
Topological Features ◽  
Wide Range ◽  
The Impact

AbstractWater distribution networks (WDNs) must keep a proper level of service under a wide range of operational conditions, and, in particular, the analysis of their resilience to pipe failures is essential to improve their design and management. WDNs can be regarded as large sparse planar graphs showing fractal and complex network properties. In this paper, the relationship linking the geometrical and topological features of a WDN to its resilience to the failure of a pipe is investigated. Some innovative indices have been borrowed from fractal geometry and complex network theory to study WDNs. Considering all possible network configurations obtained by suppressing one link, the proposed indices are used to quantify the impact of pipe failure on the system's resilience. This approach aims to identify critical links, in terms of resilience, with the help of topological metrics only, and without recourse to hydraulic simulations, which require complex calibration processes and come with a computational burden. It is concluded that the proposed procedure, which has been successfully tested on two real WDNs located in southern Italy, can provide valuable information to water utilities about which pipes have a significant role in network performance, thus helping in their design, planning and management.

scholarly journals Analysis of the daily consumption of potable water in the urban area of the Ambato city in the Province of Tungurahua-Ecuador

2021 ◽  
Vol 958 (1) ◽  
pp. 012008
Author(s):  
M Mayacela ◽  
D Moya ◽  
F Morales ◽  
L Maldonado
Keyword(s):  
Urban Area ◽  
San Francisco ◽  
Water Consumption ◽  
Water Distribution ◽  
Potable Water ◽  
Distribution Networks ◽  
Daily Consumption ◽  
Predominant Type ◽  
Daily Record ◽  
The City

Abstract The consumption of drinking water has increased over the years worldwide, therefore, the analysis of daily consumption in a certain sector is important, to know the existing demand of the population of the sector under analysis. The study of water consumption not only allows the knowledge of the amount of water consumed in a population, it also enables future projects for the design and redesign of potable water distribution networks. The main methodology for this analysis was the daily record for a period of 60 days, in each of the sectors corresponding to the urban area of Ambato city; this methodology allowed the analysis of the typical week of the sector and therefore the amount of water consumed per day in the urban sector,it was concluded that the San Francisco parish presents the highest demand for water consumption per capita with a requirement of 256.48 L/inhab/day, the predominant type of residence in the urban area of the city of Ambato is type B, which is characterized by having a typical structural system in which reinforced concrete predominates.

scholarly journals Performance-based multi-objective design and expansion of water distribution networks considering life cycle costs and future demands

2021 ◽  
Author(s):  
Swati Sirsant ◽  
M. Janga Reddy
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Water Distribution ◽  
Structural Integrity ◽  
Population Change ◽  
Capacity Expansion ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Pareto Optimal ◽  
Multi Objective

Abstract Designing the Water Distribution Networks (WDNs) consists of finding out pipe sizes such that the demands are satisfied and the desired performance levels are achieved at minimum cost. However, WDNs are subject to many future changes such as an increase (or decrease) in demand due to population change and migration, changes in water availability due to seasonal and climatic change, etc. Thus, the capacity expansion of WDNs needs to be performed such that the cost of interventions made is minimum while satisfying the demand and performance requirements at various time periods. Therefore, the current study proposed a Dynamic Programming (DP) framework for capacity expansion of WDNs and solved using Multi-Objective Self Adaptive Differential Evolution (MOSADE). The methodology is tested on three benchmark WDNs, namely Two-loop (TL), GoYang, and Blacksburg (BLA) WDNs, and applied to a real case study of the Badlapur region Maharashtra, India. The results show that the proposed methodology leads to effective Pareto optimal fronts, making it an efficient method for solving WDN expansion problems. Subsequently, an Analytical Hierarchy Process (AHP) based multi-criteria decision-making (MCDM) analysis was performed on the obtained Pareto-optimal solutions to determine the most suitable solution based on three criteria: Life Cycle Cost (LCC) of expansions, hydraulic reliability, and mechanical reliability. The main advantage of the proposed methodology is its capability to consider hydraulic performance as well as structural integrity and demand satisfaction in the face of hydraulic and mechanical failures.

scholarly journals Comparison of four models to rank failure likelihood of individual pipes

2011 ◽  
Vol 14 (3) ◽  
pp. 659-681 ◽  
Author(s):  
Yehuda Kleiner ◽  
Balvant Rajani
Keyword(s):  
Water Distribution ◽  
Distribution Networks ◽  
Classification Model ◽  
Pipe Material ◽  
Homogeneous Poisson Process ◽  
Model Based ◽  
Water Mains ◽  
Natural Variations ◽  
Non Homogeneous Poisson Process ◽  
Subsequent Failure

The use of statistical methods to discern patterns of historical breakage rates and use them to predict water main breaks has been widely documented. Particularly challenging is the prediction of breaks in individual pipes, due to the natural variations that exist in all the factors that affect their deterioration and subsequent failure. This paper describes alternative models developed into operational tools that can assist network owners and planners to identify individual mains for renewal in their water distribution networks. Four models were developed and compared: a heuristic model, a naïve Bayesian classification model, a model based on logistic regression and finally a probabilistic model based on the non-homogeneous Poisson process (NHPP). These models rank individual water mains in terms of their anticipated breakage frequency, while considering both static (e.g. pipe material, diameter, vintage, surrounding soil, etc.) and dynamic (e.g. climate, operations, cathodic protection, etc.) effects influencing pipe deterioration rates.

scholarly journals Comparison of Statistical and Machine Learning Models for Pipe Failure Modeling in Water Distribution Networks

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1153 ◽  
Author(s):  
Mónica Marcela Giraldo-González ◽  
Juan Pablo Rodríguez
Keyword(s):  
Machine Learning ◽  
Developing Countries ◽  
Statistical Models ◽  
Water Distribution ◽  
Distribution Networks ◽  
Support Vector ◽  
Failure Rates ◽  
Learning Models ◽  
Pipe Failure ◽  
Machine Learning Models

The application of statistical and Machine Learning models plays a critical role in planning and decision support processes for efficient and reliable Water Distribution Network (WDN) management. Failure models can provide valuable information for prioritizing system rehabilitation even in data scarcity scenarios, such as developing countries. Few studies have analyzed the performance of more than two models, and examples of case studies in developing countries are insufficient. This study compares various statistical and Machine Learning models to provide useful information to practitioners for the selection of a suitable pipe failure model according to information availability and network characteristics. Three statistical models (i.e., Linear, Poisson, and Evolutionary Polynomial Regressions) were used for failure prediction in groups of pipes. Machine Learning approaches, particularly Gradient-Boosted Tree (GBT), Bayes, Support Vector Machines and Artificial Neuronal Networks (ANNs), were compared in predicting individual pipe failure rates. The proposed approach was applied to a WDN in Bogotá (Colombia). The statistical models showed an acceptable performance (R2 between 0.695 and 0.927), but the Poisson Regression was the most suitable for predicting failures in pipes with lower failure rates. Regarding Machine Learning models, Bayes and ANNs exhibited low performance in the prediction of pipe failure condition. The GBT approach had the best performing classifier.

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