Download or read book A Comparison of Risk Assessment Models for Pipe Replacement and Rehabilitation in a Water Distribution System written by Lyle Nemeth and published by . This book was released on 2016 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study proved that a risk assessment model is effective in identifying critical components and developing a pipe maintenance schedule. Utilization of a risk assessment model will allow municipalities to effectively allocate funds and optimize their water distribution system.

Download or read book A Risk Analysis Model for the Maintenance and Rehabilitation of Pipes in a Water Distribution System written by Hernan Cortez and published by . This book was released on 2015 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to check its functionality, this model applied to the WDS of the City of Arroyo Grande, California. Information on the City’s distribution system was analyzed using Bentley’s WaterCAD, ESRI’s ArcGIS, MathWorks’ MATLAB and Microsoft’s Excel software to perform the analysis.

Download or read book Advances in Modeling and Management of Urban Water Networks written by Alberto Campisano and published by MDPI. This book was released on 2021-01-06 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue on Advances in Modeling and Management of Urban Water Networks (UWNs) explores four important topics of research in the context of UWNs: asset management, modeling of demand and hydraulics, energy recovery, and pipe burst identification and leakage reduction. In the first topic, the multi-objective optimization of interventions on the network is presented to find trade-off solutions between costs and efficiency. In the second topic, methodologies are presented to simulate and predict demand and to simulate network behavior in emergency scenarios. In the third topic, a methodology is presented for the multi-objective optimization of pump-as-turbine (PAT) installation sites in transmission mains. In the fourth topic, methodologies for pipe burst identification and leakage reduction are presented. As for the urban drainage systems (UDSs), the two explored topics are asset management, with a system upgrade to reduce flooding, and modeling of flow and water quality, with analyses on the transition from surface to pressurized flow, impact of water use reduction on the operation of UDSs, and sediment transport in pressurized pipes. The Special Issue also includes one paper dealing with the hydraulic modeling of an urban river with a complex cross-section.

Download or read book Deterioration and Optimal Rehabilitation Modelling for Urban Water Distribution Systems written by Yi Zhou and published by CRC Press. This book was released on 2018-05-03 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pipe failures in water distribution systems can have a serious impact and hence it’s important to maintain the condition and integrity of the distribution system. This book presents a whole-life cost optimisation model for the rehabilitation of water distribution systems. It combines a pipe breakage number prediction model with a pipe criticality assessment model, which enables the creation of a well-constructed and more tightly constrained optimisation model. The pipe breakage number prediction model combines information on the physical characteristics of the pipes with historical information on breakage and failure rates. A weighted multiple nonlinear regression analysis is applied to describe the condition of different pipe groups. The criticality assessment model combines a pipe’s condition with its hydraulic significance through a modified TOPSIS. This model enables the optimisation to focus its efforts on those important pipes. The whole life cost optimal rehabilitation model is a multiple-objective and multiple-stage model, which provides a suite of rehabilitation decisions that minimise the whole life cost while maximising its long-term performance. The optimisation model is solved using a modified NSGA-II. The utility of the developed models is that it allows decision makers to prioritize their rehabilitation strategy in a proactive and cost-effective manner.

Download or read book Prioritizing Water Pipe Replacement and Rehabilitation by Evaluating Failure Risk written by Sang Hyun Lee and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential to human life is water. Drinking water, in particular, is of utmost significance for all living creatures including man. An examination of the transmission process of drinking water reveals the high importance of pipe lines. The water pipe lines delivering water today encounter serious problems. Corrosion has caused deterioration in pipe lines, which contributes rust to drinking, a serious water quality problem. In addition, pipe line failures have caused social issues, such as suspension of water supply. This study developed a model to estimate the life expectancy and residual life of a pipe based on the assessment of failure risk in order to evaluate the current failure possibility and predict when the pipe will reach the point of failure. The developed model for estimation of residual life by failure risk was used to assess the failure risk of water pipes based on the general data and pipe sources of the Chang Won City water pipes. The efforts to diagnose and evaluate water pipes are limited to the assessment of current pipe conditions, which is why they can easily determine the priority of rehabilitation based on the current pipe conditions but have hard time getting information about how the pipes have deteriorated to the point of requiring rehabilitation. The objectives of this study are: (1) develop a model for estimating corrosion rates and residual thickness of water pipes, (2) assess loads and stress affecting water pipes, (3) to estimate damage risk, and (4) calculate safety factors. Results of the study could help reduce rehabilitation costs and secure water quality after renovation. Thus it would contribute to the safe and stable operation and management of pipe networks by increasing the life of water pipes.

Download or read book Risk Reliability and Safety Innovating Theory and Practice written by Lesley Walls and published by CRC Press. This book was released on 2016-11-25 with total page 2983 pages. Available in PDF, EPUB and Kindle. Book excerpt: Risk, Reliability and Safety contains papers describing innovations in theory and practice contributed to the scientific programme of the European Safety and Reliability conference (ESREL 2016), held at the University of Strathclyde in Glasgow, Scotland (25—29 September 2016). Authors include scientists, academics, practitioners, regulators and other key individuals with expertise and experience relevant to specific areas. Papers include domain specific applications as well as general modelling methods. Papers cover evaluation of contemporary solutions, exploration of future challenges, and exposition of concepts, methods and processes. Topics include human factors, occupational health and safety, dynamic and systems reliability modelling, maintenance optimisation, uncertainty analysis, resilience assessment, risk and crisis management.

Download or read book Urban Water Distribution Networks written by Symeon Christodoulou and published by Butterworth-Heinemann. This book was released on 2017-09-07 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Urban Water Distribution Networks: Assessing Systems Vulnerabilities and Risks provides a methodology for a system-wide assessment of water distribution networks (WDN) based on component analysis, network topology and, most importantly, the effects of a network's past performance on its seismic and/or non-seismic reliability. Water distribution networks engineers and system designers face multiple operational issues in delivering safe and clean potable water to their customers. Includes vulnerability assessment methods for water distribution pipes Discusses topological aspects and their effects on network vulnerability Explores analytical and numerical modeling methods for finding and analyzing systems vulnerabilities in water distribution networks Features real world case studies of networks under continuous and intermittent water supply operations

Download or read book Drinking Water Distribution Systems written by National Research Council and published by National Academies Press. This book was released on 2007-01-22 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protecting and maintaining water distributions systems is crucial to ensuring high quality drinking water. Distribution systems-consisting of pipes, pumps, valves, storage tanks, reservoirs, meters, fittings, and other hydraulic appurtenances-carry drinking water from a centralized treatment plant or well supplies to consumers' taps. Spanning almost 1 million miles in the United States, distribution systems represent the vast majority of physical infrastructure for water supplies, and thus constitute the primary management challenge from both an operational and public health standpoint. Recent data on waterborne disease outbreaks suggest that distribution systems remain a source of contamination that has yet to be fully addressed. This report evaluates approaches for risk characterization and recent data, and it identifies a variety of strategies that could be considered to reduce the risks posed by water-quality deteriorating events in distribution systems. Particular attention is given to backflow events via cross connections, the potential for contamination of the distribution system during construction and repair activities, maintenance of storage facilities, and the role of premise plumbing in public health risk. The report also identifies advances in detection, monitoring and modeling, analytical methods, and research and development opportunities that will enable the water supply industry to further reduce risks associated with drinking water distribution systems.

Download or read book Statistical Estimation of Water Distribution System Pipe Break Risk written by Shridhar Yamijala and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The deterioration of pipes in urban water distribution systems is of concern to water utilities throughout the world. This deterioration generally leads to pipe breaks and leaks, which may result in reduction in the water-carrying capacity of the pipes from tuberculation of interior walls of the pipe. Deterioration can also lead to contamination of water in the distribution systems. Water utilities which are already facing tight funding constraints incur large expenses in replacement and rehabilitation of water mains, and hence it becomes critical to evaluate the current and future condition of the system for making maintenance decisions. Quantitative estimates of the likelihood of pipe breaks on individual pipe segments can facilitate inspection and maintenance decisions. A number of statistical methods have been proposed for this estimation problem. This thesis focuses on comparing these statistical models on the basis of short time histories. The goals of this research are to estimate the likelihood of pipe breaks in the future and to determine the parameters that most affect the likelihood of pipe breaks. The various statistical models reviewed in this thesis are time linear and time exponential ordinary least squares regression models, proportional hazards models (PHM), and generalized linear models (GLM). The data set used for the analysis comes from a major U.S. city, and the data includes approximately 85,000 pipe segments with nearly 2,500 breaks from 2000 through 2005. The covariates used in the analysis are pipe diameter, length, material, year of installation, operating pressure, rainfall, land use, soil type, soil corrosivity, soil moisture, and temperature. The Logistic Generalized Linear Model fits can be used by water utilities to choose inspection regimes based on a rigorous estimation of pipe breakage risk in their pipe network.

Download or read book Routledge Handbook of Sustainable and Resilient Infrastructure written by Paolo Gardoni and published by Routledge. This book was released on 2018-12-17 with total page 1214 pages. Available in PDF, EPUB and Kindle. Book excerpt: To best serve current and future generations, infrastructure needs to be resilient to the changing world while using limited resources in a sustainable manner. Research on and funding towards sustainability and resilience are growing rapidly, and significant research is being carried out at a number of institutions and centers worldwide. This handbook brings together current research on sustainable and resilient infrastructure and, in particular, stresses the fundamental nexus between sustainability and resilience. It aims to coalesce work from a large and diverse group of contributors across a wide range of disciplines including engineering, technology and informatics, urban planning, public policy, economics, and finance. Not only does it present a theoretical formulation of sustainability and resilience but it also demonstrates how these ideals can be realized in practice. This work will provide a reference text to students and scholars of a number of disciplines.

Download or read book Preparing for the Replacement Era written by Brett Snider and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Water utilities throughout North America are facing a major infrastructure crisis. The large number of watermains installed during the urban expansion that occurred at the beginning of the 20th century and during the Baby-Boom are exceeding their design life and pipe breaks are increasing. Utilities are now faced with the difficult task of replacing watermains while still ensuring reliable delivery of drinking water to their customers. This thesis assists utilities in solving the aging watermain infrastructure crisis by improving pipe break prediction models, which are a critical tool in scheduling pipe replacement. First, this thesis improves the understanding of various pipe break prediction models. This research identifies machine learning models that are very accurate for ranking which pipes are likely to fail next. However, most machine learning models developed for pipe break prediction do not incorporate right censored data which results in the model being biased towards early pipe failure and thus aggressive pipe replacement schedules. This thesis improves prediction modelling by developing the first Random Survival Forest watermain failure model. The results indicate that incorporating the machine learning model into a survival analysis framework, the machine learning model is no longer biased towards early failure prediction. Therefore, utilities wishing to develop long-term pipe replacement strategies should adopt a machine learning survival analysis model. Lastly, this thesis examines the long-term trends of Canadian pipe breaks. The findings from this research identify that break rates for major water utilities in Canada have not increased substantially since the 1990s. Furthermore, this research quantifies the impact pipe rehabilitation has played in lowering break rates over the last three decades. Overall, this thesis advances the research into pipe break prediction models by identifying the impact of limited datasets on various prediction models, developing an advanced machine learning survival analysis model that accurately predicts time-to next failure, and quantifying the impact of pipe rehabilitation techniques on long-term break trends in Canada. This information is significant to many utilities throughout Canada and much of the developed world as they begin to face an aging watermain infrastructure crisis that threatens the supply of clean drinking water.

Download or read book Risk Benefit Analysis in Water Resources Planning and Management written by Yacov Haimes and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ronald M. North President Universities Council on Water Resources People sense intuitively that the world in which we live is not free of risk. Every decision, every action, even the refusal to either act or decide involves some element of risk. Perhaps, because we accept relatively low levels of risk in our daily activi ties, we tend to minimize the existence of risk and thereby fail to include risk assessment in those decisions and actions which could be improved through a risk assessment process. However, our casual approach to risk assessment seems to stem largely from the diffi culties inherent in measuring risk rather than from any lack of cognizance of the existence of risk. This conclusion is evidenced by the many statements in official documents relating to planning and evaluation which suggest that risk assessments should be con ducted but do not provide the mechanism for such assessments nor do they encourage their consideration in the decision making process. This conference on Risk/Benefit Analysis in Water Resources Planning and Management is notable because it attempts to identify and evaluate the mechanisms available for risk assessment which might be useful in water resources planning and management efforts. These proceedings bring together the thoughts of professional per sons who have struggled with the problems of risk assessment and who have contributed to the refinement of both theoretical and pragmatic solutions for the improvement of risk assessment processes.

Download or read book Water Distribution Network Rehabilitation written by Yehuda Kleiner and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most expensive component of a water supply system is the distribution network. Aging water supply infrastructure, coupled with the continuous stress placed on the pipes by operational and environmental conditions, have led to system deterioration which manifests itself in increased operation and maintenance costs, water losses, reduction in the quality of service and reduction in the quality of water supplied. In this thesis, a methodology is proposed to select, for each pipe in an existing network, the rehabilitation alternative and the time of its implementation, so as to minimize the cost of the rehabilitation investment and all maintenance costs over a pre-defined time horizon and subject to certain constraints. The methodology explicitly considers the deterioration over time of both the structural integrity and the hydraulic capacity of every pipe in the system. The cost associated with each pipe in the network is calculated as the present value of an infinite stream of costs. The proposed method, named the multistage network rehabilitation analysis procedure (MNRAP) is based on a dynamic programming approach combined with partial and (sometimes) implicit enumeration schemes. A computer program was developed to implement the methodology. Subsequently, the validity of the MNRAP was established in two ways: (1) Some simple systems were exhaustively enumerated for all possible combinations of rehabilitation alternatives selection and scheduling, and their minimum cost sequences were compared to those obtained by applying MNRAP. An excellent agreement was demonstrated between the two sets of results. (2) A study was conducted in which six water utility managers from the Greater Toronto Area and the Region of Waterloo (the participants) were presented with a sample water distribution system including all pertinent data that would typically be available when preparing a long-term rehabilitation program. The participants were required to implement their best engineering judgment and analysis tools in determining an optimal rehabilitation policy, subject to stated constraints. These policies were then compared to that obtained by the MNRAP. The comparison demonstrated the advantages of MNRAP over existing analysis practices; (a) in its comprehensiveness and (b) in the explicit, robust manner with which the economics and the hydraulics of the water distribution system are simultaneously considered over a planning time horizon. In conclusion, the MNRAP promises to provide a valuable decision support system for engineers and decision makers in devising long-term network rehabilitation plans.

Download or read book Optimal Rehabilitation replacement Model for Water Distribution Systems written by Joong Hoon Kim and published by . This book was released on 1992 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Business of Water written by Steve Maxwell and published by . This book was released on 2008 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a compilation of recent JAWWA articles regarding the challenges and opportunities in the water market. It addresses topics such as the global water problem, the global water industry, plus trends and developments in the industry.

Download or read book Detailed Water Quality Modeling of Pressurized Pipe Systems and Its Effect on the Security of Municipal Water Distribution Networks written by Ryan Glen Austin and published by . This book was released on 2011 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current study expands on the body of knowledge associated with water distribution system security. The three main chapters focus on 1) the effectiveness of an incomplete mixing model (AZRED-I) with respect to multi-objective sensor placement decisions; 2) risk assessment as a tool for evaluating vulnerability and making sensor placement decisions; and 3) experimental verification of a combined axial-dispersion and incomplete-mixing water quality model (AZRED-II). The study concludes that water quality models do impact sensor placement decisions, especially in highly interconnected networks; that risk assessment is a valuable evaluation tool for providing information concerning a system's vulnerability to contamination and also information that can affect sensor placement decisions; and that AZRED-II is superior to other water quality models at predicting the spatiotemporal pattern of a pulse through a distribution network with cross junctions under laminar flow. The other sections of the study describe the connection that exists between water distribution security and water quality models.

Download or read book Failure Rate Prediction Models of Water Distribution Networks written by Seyed Farzad Karimian and published by . This book was released on 2016 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The economic, social and environmental impacts of water main failures impose a great pressure on utility managers and municipalities to develop reliable rehabilitation/replacement plans. The Canadian Infrastructure Report Card 2012 stated that 15.4% of Canadian water distribution systems was in a ?fair? to ?very poor? condition with a replacement cost of CAD 25.9 billion. The ?fair?, ?poor? and ?very poor? conditions represent the beginning of deterioration, nearing the end of useful life and no residual life expectancy, respectively. The majority of municipalities in Canada do not possess complete dataset of water distribution networks. The annual number of breaks or breakage rate of each pipe segment is known as one of the most important criteria in condition assessment of water pipelines. The main objective of this research is to develop a research framework that circumvent the limitations of existing studies by: 1) identifying the most critical factors affecting water pipe failure rates, 2) determining the best mathematical expression for predicting water pipeline failure rate 3) developing deterioration curves, and 4) deploying sensitivity analysis to recognize the effect of each input change on the breakage rate. The proposed research framework utilizes Best Subset regression to recognize the most effective factors on water pipelines. Best-Subset Algorithm is a procedure to find the best combination of variables to predict the water pipe failure rate among all possible candidates. Once the process of critical factor selection is performed, selected variables are employed to predict the number of breaks of water pipes using Evolutionary Polynomial Regression (EPR). The EPR is an intuitive data mining technique performed in two stages: 1) the search for the best model using Multi-Objective Genetic Algorithm (MOGA), and 2) the parameter estimation for the model using Least Square Method. The predicted number of breaks, computed by EPR, is utilized to develop deterioration curves by applying Weibull distribution function. Finally, sensitivity analysis is performed to: 1) recognize the effect of changing each input on the failure rate, and 2) study the relationship between the selected inputs and the output. The developed research framework is applied into two case studies to test its effectiveness. The case considers the water distribution networks in the City of Montréal, Canada and the City of Doha, Qatar. Physical factors, such as age, length, diameter and pipe material were identified as the most critical factors to affect the failure rate of pipes. The results indicate that the developed models successfully estimated the number of breaks for the City of Montreal and City of Doha with a maximum R-Squared of 89.35% and 96.27%, respectively. Also, it is tested by using 20% of each dataset and promising results were generated with a maximum R-Squared of 84.86% and 74.39% for dataset of Montreal and Doha respectively. This demonstrates the accuracy and robustness of the developed models in assessing and analyzing water distribution networks. The developed model is useful for municipalities and decision makers to prioritize the maintenance, repair, rehabilitation, and budget allocation of water distribution networks.