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Статті в журналах з теми "Pipe condition assessment"
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van Laarhoven, Karel, Jip van Steen, Frank van der Hulst, and Hector Hernandez Delgadillo. "CT Scans of Asbestos Cement Pipes as a Reference for Condition Assessment of Water Mains." Water 13, no. 17 (August 30, 2021): 2391. http://dx.doi.org/10.3390/w13172391.
Повний текст джерелаАнотація:
The water distribution network of The Netherlands contains around 30,000 km of asbestos cement (AC) pipes, which constitutes around 25% of the total network. As a pipe material, AC has a relatively poor performance, and therefore is a high priority for renewal. To help decide an effective order of replacement, the water utilities need condition assessment techniques that help them determine which pipes have the highest risk of failure. In the presented work, X-ray computed tomography (CT) was used to measure the degradation of AC pipes taken out of the field. These scans provide a description of the pipe degradation with unmatched detail. The results are compared with strength tests performed on the same pipes, revealing that detailed knowledge of the complete pipe degradation is more important than previously assumed. Moreover, comparison of the CT results to those of a commercial, non-destructive inspection technique was used as a new avenue for validation of this technique, demonstrating its future usefulness for attaining the detailed measurement of pipe degradation required by water utilities.
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Atique, Farzana, and Nii Attoh-Okine. "Copula parameter estimation using Bayesian inference for pipe data analysis." Canadian Journal of Civil Engineering 45, no. 1 (January 2018): 61–70. http://dx.doi.org/10.1139/cjce-2017-0084.
Повний текст джерелаАнотація:
Water main systems are aging and becoming a growing concern for maintenance. The structural deterioration of water mains is affected by different factors, such as pipe age, pipe material, soil condition, and pipe size, among others. Various methods of modeling have been used to predict the failure of water mains. Since pipe networks are underground and obtaining data on pipe conditions is very costly, statistical modeling has been widely used for pipe condition assessment. An emerging statistical method known as copula modeling is used here for pipe data analysis. The copula method is very useful in cases where marginals belong to different families of distributions. It is also useful for generating a large number of data points when it is difficult to obtain a data set, as is the case for pipe condition assessment, and where data sets have random variables belonging to non-Gaussian family distributions. Different copula families are applied here to model the dependency between the pipe age and repair age of pipes. The paper uses a Bayesian framework to estimate the parameter values in the copula model. This approach offers an additional option for estimating copula parameters for pipe data.
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Shi, He, Jinzhe Gong, Peter R. Cook, John W. Arkwright, Gretel M. Png, Martin F. Lambert, Aaron C. Zecchin, and Angus R. Simpson. "Wave separation and pipeline condition assessment using in-pipe fibre optic pressure sensors." Journal of Hydroinformatics 21, no. 2 (February 12, 2019): 371–79. http://dx.doi.org/10.2166/hydro.2019.051.
Повний текст джерелаАнотація:
Abstract The use of two pressure transducers in close proximity can enable the separation of the directional travelling pressure waves in pipelines. However, the implementation of this measurement strategy in real water pipes is difficult due to the lack of closely located access points. This paper reports the use of a customised in-pipe fibre optic pressure sensor array for hydraulic transient wave separation and pipeline condition assessment. The fibre optic pressure sensor array can be inserted into a pressurised pipeline through a single access point. The array consists of multiple fibre Bragg grating (FBG)-based pressure sensors in close proximity (∼0.5 m apart). A previously developed wave separation algorithm is adapted to analyse the transient pressure measurement from the FBG sensors. The resultant directional pressure waves are then used to detect pipe sections with a thinner wall thickness. A challenge is the influence of the in-pipe fibre optic sensing cable on the transient pressure measurement. The impact is analysed and adjustments to the pipeline condition assessment algorithm are undertaken to resolve the issue. The successful experimental application verifies the usefulness of the in-pipe fibre optic sensor array, which can facilitate transient-based pipeline condition assessment for buried water pipes with limited access points.
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Nguyen, Lam Van, and Razak Seidu. "Application of Regression-Based Machine Learning Algorithms in Sewer Condition Assessment for Ålesund City, Norway." Water 14, no. 24 (December 7, 2022): 3993. http://dx.doi.org/10.3390/w14243993.
Повний текст джерелаАнотація:
Predicting the condition of sewer pipes plays a vital role in the formulation of predictive maintenance strategies to ensure the efficient renewal of sewer pipes. This study explores the potential application of ten machine learning (ML) algorithms to predict sewer pipe conditions in Ålesund, Norway. Ten physical factors (age, diameter, depth, slope, length, pipe type, material, network type, pipe form, and connection type) and ten environmental factors (rainfall, geology, landslide area, population, land use, building area, groundwater, traffic volume, distance to road, and soil type) were used to develop the ML models. The filter, wrapper, and embedded methods were used to assess the significance of the input factors. A dataset consisting of 1159 inspected sewer pipes was used to construct the sewer condition models, and 290 remaining inspections were used to verify the models. The results showed that sewer material and age are the most significant factors, otherwise the network type is the least contributor affecting the sewer conditions in the study area. Among the considered ML models, the Extra Trees Regression (R2 = 0.90, MAE = 11.37, and RMSE = 40.75) outperformed the other ML models and it is recommended for predicting sewer conditions for the study area. The results of this study can support utilities and relevant agencies in planning predictive maintenance strategies for their sewer networks.
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Bechet, Quentin, Xavier Philoleau, Melissa Mellado-Ruiz, Amanda Siqueira, and Michelle Aguilar. "Using artificial intelligence to improve pipe condition assessment." Water e-Journal 5, no. 3 (2020): 1–12. http://dx.doi.org/10.21139/wej.2020.020.
Повний текст джерелаАнотація:
Inspection and condition assessments of network infrastructure are critical for water utilities and city councils to ensure the structural integrity and functionality of sewer pipes and stormwater drains. These assessments are necessary to identify the pipes requiring rehabilitation before they deteriorate past the point of renewal. In practice, these assessments are performed manually through camera inspection of the pipes. However, the visual observation of the resulting footage can be biased by the operator subjectivity. VAPAR.Solutions is a cloud platform that automates condition assessment directly from a pipe’s CCTV footage. In this context, VAPAR, an Australian-based company, developed a deep-learning algorithm to code inspection videos automatically and consistently. This study aimed to evaluate the performance of this auto-coding algorithm by using a dataset of 203 inspection videos captured in stormwater and sewer pipes in Victoria, Australia. This study revealed that the VAPAR algorithm missed fewer defects in sewer and stormwater pipes (13.2%) than the operator during visual inspection (36.6%). The VAPAR algorithm was, however, ‘over-sensitive’ and generated 28.1% of false alarms, against 7.8% for the operator. This study also revealed that the VAPAR algorithm was significantly more accurate than the operator at grading the pipes, with an accuracy between 76.3-79.8% against 48.5-52.2% for the operator.
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Zhu, Juanjuan, Joby B. Boxall, Andrew F. Hills, Rob S. Dwyer-Joyce, Sean R. Anderson, and Richard P. Collins. "Assessing Ground Support of Plastic Pipes Using Ultrasound." Infrastructures 6, no. 2 (February 19, 2021): 30. http://dx.doi.org/10.3390/infrastructures6020030.
Повний текст джерелаАнотація:
The ability to detect early signs of failure in buried pipe infrastructure is necessary to facilitate the continued use of ageing infrastructure for delivery of society’s essential services and move beyond disruptive and expensive reactive maintenance and repair. This paper reports detailed experiments on the use of in-pipe ultrasound techniques for assessment of ground conditions around buried plastic pipes. Two sets of ultrasonic experiment on the soil conditions are presented: (1) existence, shape, and dimension of void, and (2) water content in the soil. The ultrasound technique is shown to be capable for detecting water filled voids and assessing the soil support, critical early indicators of failure. The technique requires water as the transmission media hence is naturally suited to application in operational water distribution systems. The work represents an important advance in in-pipe condition assessment of plastic pipes, demonstrates the practical capability of the ultrasound technique, which is critical for progression towards proactive maintenance, offering cost and service improvements.
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Steed, H., S. Mandhle, and E. Steitle. "Retooling Condition Assessment When You Can’t Inspect Pipe." Proceedings of the Water Environment Federation 2016, no. 13 (January 1, 2016): 5339–57. http://dx.doi.org/10.2175/193864716819706239.
Повний текст джерела
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Mashford, John, David Marlow, and Stewart Burn. "An Approach to Pipe Image Interpretation Based Condition Assessment for Automatic Pipe Inspection." Advances in Civil Engineering 2009 (2009): 1–11. http://dx.doi.org/10.1155/2009/317097.
Повний текст джерелаАнотація:
Condition assessment forms an important part of the asset management of buried pipelines. This is carried out through the use of inspection systems which usually consist of an image acquisition device attached to a mobile robotic platform. Complete or partial automation of image interpretation could increase the efficiency and objectivity of pipe inspection. A key component of an automatic pipe inspection system is the segmentation module. This paper describes an approach to automatic pipe inspection using pixel-based segmentation of colour images by support vector machine (SVM) coupled with morphological analysis of the principal component of the segmented image. The morphological analysis allows the principal component of the segmented image to be decomposed into the pipe flow lines region, the pipe joints, and adjoining defects. A simple approach to detecting pipe connections using fuzzy membership functions relating to defect size and location is also described.
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Arsénio, André Marques, Jan Vreeburg, and Luuk Rietveld. "Index of Joint Condition for PVC push-fit joints." Water Supply 14, no. 5 (May 13, 2014): 857–65. http://dx.doi.org/10.2166/ws.2014.043.
Повний текст джерелаАнотація:
The Index of Joint Condition (IJC) for polyvinyl chloride (PVC) push-fit joints, discussed in this article, was derived from installation guidelines and from destructive laboratory tests. The IJC is presented in a graphical framework and is a powerful tool to employ in order to visualize and compare, in situ, results obtained during condition assessment of PVC joints. The graphical results can also be translated into a numerical grade that allows comparing the conditions of various pipes and of individual joints. The applicability of the IJC is demonstrated in the condition assessment of 222 joints inspected in eight different sessions that encapsulate more than 2 km of older (more than 40 years) and newer pipes (less than 2 months). While, for the new pipe, all joints were considered to be in good condition – low replacement priority –, several joints in older pipes were considered to have high replacement priority.
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Chen, C. N., and H. Y. Chen. "Distributions of Pore Water Pressure Surround a Horizontal Drain Pipe on a Retaining wall Under Steady State Condition." Journal of Mechanics 29, no. 2 (December 20, 2012): 263–72. http://dx.doi.org/10.1017/jmech.2012.132.
Повний текст джерелаАнотація:
AbstractThis article presents the results from a study of drainage rates and groundwater pressure distributions surrounding a horizontal drain pipe. The pipe is assumed to be applied on a retaining wall and reached a steady state condition. The optimized design pattern for horizontal drain pipes on a retaining wall is deeply related to the efficiency of dissipation of groundwater and the pore pressure behind the wall. Therefore, simulations of groundwater flow through a single horizontal drain pipe with different sizes (diameters and lengths) and depths by a 3-D finite element program model would lead us to find out the mechanism of the drainage pattern. The study has revealed the equalized water pressure contours surrounding the horizontal drain pipe exhibited horn shapes distributions. The biggest but still has a closed shape of horn was named Characterized Iso-pressure Surface (CIPS) in this research. It was found to be a good object to reflect the effects of single drain pipe so as to explore the mechanisms of drainage pattern. This research conducted a series study of dimension factor influence. It could be a help in developing assessment and design methods for horizontal drain pipes applied to the retaining wall.
Дисертації з теми "Pipe condition assessment"
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Tanyanyiwa, Craig Tinashe. "Towards practical pressure-based leakage characterisation of water distribution pipes with a novel pipe condition assessment device." Master's thesis, Faculty of Engineering and the Built Environment, 2019. https://hdl.handle.net/11427/31785.
Повний текст джерелаАнотація:
Leakage detection and management have been proposed as effective ways of mitigating and managing water losses in an age where water scarcity has become prevalent. To this end, several methods have been developed and suggested with different benefits and drawbacks The presently available leakage detection methods, however, fail to identify and characterise the leakage while simultaneously assessing the condition of the water distribution network (WDN). This function is imperative for understanding and addressing leakage. WDN assessments are also important as knowledge of the network parameters helps in reducing water losses through planned infrastructure maintenance programmes. A pipe condition assessment device (PCAD) was thus developed which can detect, characterise leakage and assess the condition of the WDN. However, the efficacy and reliability of this device had not yet been established. In this study, the device was used to characterise leakage and assess system conditions in water networks. Initially, laboratory tests on six known leak types were conducted on a standardised laboratory setup. The leakage characteristics of these pipes were found through regression analysis. The results from the tests established that to 95% level of confidence; the standardised setup can produce repeatable and comparable results to previous studies. The accuracy of the PCAD instrumentation was verified and the device calibrated, the same pipes were then tested on the standardised setup using the PCAD. An overlap of the results from the laboratory experiments and the PCAD revealed that to 95% level of confidence, the device could adequately characterise leakage in pipes. A low variance of less than 4% of the mean parameter, across all tests conducted using the PCAD, informed that the results obtained through using the PCAD are repeatable and reliable. Field tests in the Kensington DMA were done and revealed the limitations of the device, such as its inability to characterise leakage in pipe sections that cannot be successfully isolated. However, in pipelines that were successfully isolated, the PCAD was able to detect and identify leakage characteristics in water networks and aid in conducting maintenance runs. Consequently, this study contributed to the body of knowledge by statistically establishing that the PCAD could adequately, and reliability characterise leakage in real water distribution networks.
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Ge, Shaoqing. "Development of a Numerical Model to Analyze the Condition of Prestressed Concrete Cylinder Pipe (PCCP)." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/82163.
Повний текст джерелаАнотація:
Prestressed Concrete Cylinder Pipe (PCCP) is a large-diameter and high-pressure conduit for drinking water and wastewater transmission. Due to its large diameter, high pressure, and mode of breakdown, PCCP failures usually have catastrophic consequences. To mitigate failures, it is very important to assess the condition of the pipe and take proactive measures, such as repair, rehabilitation, or replacement.
There are many challenges in assessing the condition of PCCP. PCCP has a complex structure with several layers of materials (e.g. mortar coating, prestressing wire, steel cylinder, and concrete core) working together under loading. This means that there are many factors that can cause pipe failure, and that failure mechanisms are complicated. Data collection could be difficult, and existing data are often unavailable or unreliable.
Considerable research has been conducted by scholars and engineers in developing models to evaluate the condition of PCCP. There are mainly two types of models: statistical models, and numerical models using finite element method. Statistical models consider only a few factors, such as pipe age and failure rate, to predict the failure of PCCP. However, the failure of PCCP can be caused by many other factors including pipe material, and loading conditions. Models only considering a few factors are not robust enough for reliable results. The current numerical models assume that all broken wires are centrally distributed in the same location and broken wires have no prestress, thus all broken wires are completely removed from the model. These assumptions could be overly conservative when actual broken wires are distributed in different locations along the pipeline and broken wires have remaining prestress due to the bond between the wire and mortar coating. Therefore, a more comprehensive numerical model is needed to have a better understanding of the condition of PCCP.
In this research, an extensive literature and practice review was conducted on PCCP failures to understand the critical factors that affect pipe condition. The available technologies commonly used to detect pipe defects were reviewed in order to better understand the accuracy and uncertainties of the collected data. Existing models were reviewed to better understand their limitations and to advance the research on condition analysis of PCCP using numerical models.
Based on these comprehensive reviews, this dissertation proposed a numerical model to analyze the condition of PCCP for its long-term performance management. Detailed structural components such as concrete cores, prestressing wires, steel cylinder, and mortar coating were modelled. The interactions between different layers of pipe components were considered. An algorithm was proposed to account for the bond between the prestressing wire and mortar coating, which is a critical factor for the condition of PCCP with broken wires. A FORTRAN program was developed to assign linear stress distribution between the broken point and the full-prestress resuming point.
The proposed numerical model was verified utilizing data from lab tests and forensic study. Lab test data helped to understand the functionality of the model and to verify the model parameters used in analyzing pipe components and the simulation of interactions between different layers. The forensic data helped to verify the model under actual field working conditions of the pipe.
Validation of the proposed numerical model was conducted using a 66-inch Embedded Cylinder Pipe and two Lined Cylinder Pipes (42-inch and 48-inch, respectively) from a water utility. In the validation, field data were collected for model development. The simulation results were consistent with the field observation, which proved the validity and applicability of the proposed numerical model in practice.
A series of sensitivity studies were conducted to investigate the impact of longitudinal and circumferential location on the structural integrity of the pipe. These investigations showed that considering the actual longitudinal and circumferential location of broken wires is very important to get accurate analysis of pipe condition, while assuming that all broken wires fail in one longitudinal location (assumptions by current numerical models for PCCP) will overestimate the actual damage to the pipe caused by broken wires.
To consider the bedding condition, a critical factor for PCCP, the four most common bedding types found in practice were analyzed. Results show that poor bedding could lead to cracks in PCCP, which could cause corrosion in prestressing wires. Therefore, it is very important to account for bedding conditions in the PCCP analysis.
The model presented in this dissertation is more comprehensive and robust compared with existing numerical models, and could provide a better understanding of the condition of PCCP. This is because the proposed model considers the contribution of remaining prestress in broken wires due to the bond between the wire and mortar coating. This model can consider the actual longitudinal and circumferential location of broken wires rather than centrally distribute them, and it can consider the actual bedding locations, and the interaction between different layers of materials. This model was calibrated using lab test data and forensic data, and was further validated using field data which showed consistence between simulation results and field observations.
The proposed model does have limitations due to limited availability of data and assumptions. Material tests were not conducted to verify the material properties used in the model, which could cause accuracy issues in the results. A full-scale simulation of the interaction between prestressing wire and mortar coating was not considered because it could significantly increase the computation time. Lab tests were not conducted to verify the parameters used for the simulation of interaction between concrete core and steel cylinder which could lead to accuracy problems. Finally, it is acknowledged that the model was only validated in one water utility and validations in more geographically distributed utilities might further test the model's validity and robustness.
Nonetheless, the comprehensiveness and robustness of this proposed model improved the analysis of the condition of PCCP. The findings and results of this research will provide guidance for better management of PCCP pipelines for water utilities, and provide reference for future research on numerical modeling of PCCP as well.Ph. D.
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Yan, Jimin. "Risk assessment of contaminant intrusion into water distribution system." Thesis, Loughborough University, 2006. https://dspace.lboro.ac.uk/2134/7767.
Повний текст джерелаАнотація:
It is recognised through current literature that contaminantin trusion is a primary threat leading to degradation of water quality and threat to human health. The problem is more serious in developing countries where the water supply is intermittent and water distribution system crisscross with sanitary systems. Therefore there is a need to develop the methodology that enables the decision makers and engineers to undertake actions to minimise the risk of contamination of water. The researchs tudy presentedin this thesis addresses these water quality issues by developing the appropriate modelling tools to minimize the risk of contaminant intrusion. The conceptual framework proposed in this study consists of a risk based approach where the process of contaminant intrusion into the systems is traced to know the hazards of contaminant intrusion and vulnerability of the system. The risk of contaminant intrusion into the pipes of a water distribution system is then estimated as the function of hazards and vulnerability. A suit of four models is developed based on this framework. The first model is a water distribution pipe condition assessment model that simulates the potential pathway for contaminant ingress into water pipes by relating it to the deterioration/condition of the pipes. The condition of each pipe is assessed by means of numerous factors related to physical, environmental and operational aspects of the water distribution system. These factors are grouped into different indicators at three levels, depending on the nature of influence of each factor on the deterioration process of the pipe. The uncertainties inherent in these pipe condition indicators are described with fuzzy set theory. A distance based multi-criteria decision making method-fuzzy composite programming has been applied to combine the multilevel pipe condition indicators to form a single indicator to rank the condition of the pipes. The second model is a water flow and contaminant transport modelling tool. This model predicts the envelope of pollution emanating from pollution sources (contaminant zone) and simulates the seepage and contaminant transport in this zone. It is assumed that the seepage of contaminant from pollution sources such as unlined canal/drains and surface water bodies follow saturated flow while from pollution sources such as sewer pipelines, lined canals/drains follow unsaturated flow. Accordingly Richard/Green Ampt equations (unsaturated flow) and Darcy's equation (saturatedf lows) are coupled with advection-diffusion equations that account for water flow and contaminant transport respectively. The third model, the contaminant ingress model, identifies sections of pipe of water distribution system within contaminant zone by combining the outputs from the contaminant seepage model with spatial analysis. The fourth model, the risk assessment model, identifies the risk of contaminant intrusion into a water distribution system from the outputs of the above three models, namely the vulnerability of the water distribution pipe (pipe condition assessment model), the contaminant concentration(contaminant seepage model) and section of pipe in contaminant zone (contaminant ingress model). All these models have been integrated into ArcView GIS to form a decision support system (Improved Risk Assessment of Water Distribution System) and applied to a real water distribution system in Guntur, India for which water pipe network data and data for pollution sources were collected. The modelling results are presented as risk maps that show the potential areas that are under threat of contamination with relative risk scores. It is envisaged that the developed modelling tools will be used by water utilities in developing countries to improve the water quality management by identifying vulnerable areas and understanding threats that exist to the water distribution systems.
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Agarwal, Manu. "Developing a Framework for Selecting Condition Assessment Technologies for Water and Wastewater Pipes." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/34771.
Повний текст джерелаАнотація:
Beneath North America's roads lie 1.6 million miles of pipeline that provides users with potable water and carry away wastewater. These buried infrastructure systems have been functioning for duration longer than their intended design life, often with little or no repair. Asset management of pipeline systems pose a major challenge for most municipalities due to budgetary constraints, demand for quality service, and need to preserve existing pipeline infrastructure. The first step in developing and implementing a comprehensive asset management plan is to perform a condition assessment.
There is a gamut of inspection and monitoring technologies available to enable the condition assessment of pipelines. All of these have advantages and limitations, which determine the performance quality and effectiveness of an individual technology for particular utility assets. Unfortunately, utilities choose technologies not suitable for their specific assets and collect data that is not useful for understanding the condition of their system.
The objective of this thesis is to develop a framework for the effective selection of condition assessment technologies for water and wastewater utilities. A Microsoft-Excel based framework is developed to help the utility managers in selecting condition assessment technologies for their water and wastewater pipeline assets.
The recommended tool selection approach uses a multi-step exclusion protocol in which the tools are excluded on the basis of their applicability relating to technical feasibility and technical suitability for a particular situation. Usable tools are then compared against a performance and cost database to determine performance and cost in a given project/ utility condition.
This thesis provides a brief description and review of 24 non-destructive commercialized condition assessment technologies, including the principal and implementation considerations. A framework for decision system tool was developed to facilitate utilities in selecting appropriate condition assessment technologies. This framework could facilitate the selection of usable technologies by excluding the options which are not technically feasible and suitable. The user can then further explore the usable tools and determine the most suitable technologies for their assets.
The data considered in the research is provided by technology providers, thus it may lack complete understanding of the capabilities and limitations of technology. This thesis also presents a case study which highlights the existing gap between the understanding of capabilities and limitations of various technologies.
A program is developed as a part of this thesis, Condition Assessment Selection Tool (CAST), which consists of performance and economic database, a graphical user interface to facilitate user input, and the results of the comparison of each usable technology in the database to the project information provided by the user for their assets. The results are presented as performance indices and economic indices indicating the performance and technology cost of usable technologies. A data reliability index was also developed to provide a scale for comparing the reliability of the existing data in the database.Master of Science
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Nemeth, Lyle John. "A Comparison of Risk Assessment Models for Pipe Replacement and Rehabilitation in a Water Distribution System." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1599.
Повний текст джерелаАнотація:
A water distribution system is composed of thousands of pipes of varying materials, sizes, and ages. These pipes experience physical, environmental, and operational factors that cause deterioration and ultimately lead to their failure. Pipe deterioration results in increased break rates, decreased hydraulic capacity, and adverse effects on water quality. Pipe failures result in economic losses to the governing municipality due to loss of service, cost of pipe repair/replacement, damage incurred due to flooding, and disruptions to normal business operations. Inspecting the entire water distribution system for deterioration is difficult and economically unfeasible; therefore, it benefits municipalities to utilize a risk assessment model to identify the most critical components of the system and develop an effective rehabilitation or replacement schedule.
This study compared two risk assessment models, a statistically complex model and a simplified model. Based on the physical, environmental, and operational conditions of each pipe, these models estimate the probability of failure, quantify the consequences of a failure, and ultimately determine the risk of failure of a pipe. The models differ in their calculation of the probability of failure. The statistically complex model calculates the probability of failure based on pipe material, diameter, length, internal pressure, land use, and age. The simplified model only accounts for pipe material and age in its calculation of probability of failure. Consequences of a pipe failure include the cost to replace the pipe, service interruption, traffic impact, and customer criticality impact. The risk of failure of a pipe is determined as the combination of the probability of failure and the consequences of a failure. Based on the risk of failure of each pipe within the water distribution system, a ranking system is developed, which identifies the pipes with the most critical risk. Utilization of this ranking system allows municipalities to effectively allocate funds for rehabilitation.
This study analyzed the 628-pipe water distribution system in the City of Buellton, California. Four analyses were completed on the system, an original analysis and three sensitivity analyses. The sensitivity analyses displayed the worst-case scenarios for the water distribution system for each assumed variable. The results of the four analyses are provided below.
Risk Analysis
Simplified Model
Complex Model
Original Analysis
All pipes were low risk
All pipes were low risk
Sensitivity Analysis: Older Pipe Age
Identified 2 medium risk pipes
Identified 2 medium risk pipes
Sensitivity Analysis: Lower Anticipated Service Life
Identified 2 medium risk pipes
Identified 9 high risk pipes and 283 medium risk pipes
Sensitivity Analysis: Older Pipe Age and Lower Anticipated Service Life
Identified 1 high risk pipe and 330 medium risk pipes
Identified 111 critical risk pipes, 149 high risk pipes, and 137 medium risk pipes
Although the results appeared similar in the original analysis, it was clear that the statistically complex model incorporated additional deterioration factors into its analysis, which increased the probability of failure and ultimately the risk of failure of each pipe. With sufficient data, it is recommended that the complex model be utilized to more accurately account for the factors that cause pipe failures.
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.
Keywords: Water Distribution System/Network, Risk of Failure, Monte Carlo Simulation, Normal Random Variable, Conditional Assessment, Sensitivity Analysis.
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Yaminighaeshi, Hamidreza. "Probability of failure analysis and condition assessment of cast iron pipes due to internal and external corrosion in water distribution systems." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/14079.
Повний текст джерелаАнотація:
Corrosion of cast iron pipes in distribution systems can lead to the development of corrosion pits that may reduce the resistance capacity of the pipe segment, resulting in mechanical failure. These pipes have a tendency to corrode externally and internally under aggressive environmental conditions. The mechanical failure of pipes is mostly the result of this structural weakening coupled with externally, environmental, and internally, operational, imposed stresses. While external corrosion has been shown to significantly affect the likelihood of mechanical failure, the risk of failure may be further heightened if internal corrosion is occurring.
This thesis develops a methodology for estimating the probability of mechanical failure of cast iron pipes due to internal corrosion that incorporates the relationship between chlorine consumption and the rate of internal corrosion in a cast iron pipe. A probability analysis is developed that incorporates the internal corrosion model as well as the Two-phase nonlinear external corrosion model to calculate the overall probability of mechanical failure. Monte Carlo Simulation (MCS), First Order Reliability Method (FORM)-, and Second Order Reliability Method (SORM)-based approaches are used to estimate the probability of mechanical failure.
Next, a methodology is developed for analyzing pipe condition based on the data resulting from the probability of mechanical failure analysis incorporating internal and external corrosion. A modeling strategy inspired by survival analysis is used to obtain the predicted number of pipe breaks for a given exposure time. The likelihood of failure at a given residual pipe wall thickness is estimated and coupled with the predicted number of pipe breaks as surrogates for pipe condition. These condition indices may support decisions regarding replacement planning and can be coupled with economic assessment models in the development of future asset management strategies.
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Cortez, Hernan. "A Risk Analysis Model for the Maintenance and Rehabilitation of Pipes in a Water Distribution System: A Statistical Approach." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1442.
Повний текст джерелаАнотація:
ABSTRACT
The network of pipes in potable water distribution systems (WDS) are comprised of thousands of pipes made of various materials including PVC, concrete, cast iron, and steel, among several others. The pipes are subjected to internal and external conditions that lead to their failure. Stress conditions include, but are not limited to internal pressures, traffic loading, and corrosion. The deterioration of a pipe decreases its mechanical strength which results in an increase of its probability of failure. Failures lead to loss of service which translates to loss of money due to the cost of repairs and buildup of traffic caused by street closures.
The focus of this study is the pipe network underneath cities that make it possible for communities to have access to potable water. The objective of this analysis is to evaluate the physical conditions of each pipe in a water distribution system in order to assess its probability of failure and ultimately calculate the risk associated with each pipe in the case that it were to fail. This model focuses only on the pipes of the WDS and does not take into consideration fittings, pumps, and other network components. This model assesses pipe age, material, diameter, internal pressure, traffic loading (industrial or residential), and length to determine the probability of failure. It then utilizes several economic factors such as material cost, customer criticality, demand, traffic impact, and land use to calculate the risk associated with each pipe. The risk associated with each pipe can then be used as a ranking system to identify the most vulnerable pipes, those with the highest economic impact upon failure. Identifying the pipes with the highest risk allows municipalities to better allocate funds for maintenance or replacement of pipes. It highlights the most critical pipes within a network of thousands.
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.
The risk analysis model provided 3 pipes within the distribution system made of cast iron as having a high probability of failure and a critical level of risk. A critical level of risk is defined as falling within the highest range of risk within this study. Considering that only 3 pipe segments were highlighted as having a Critical Risk, 4 as High Risk, and 6 as Medium Risk, in a system of 3572 pipes indicates that the model functions properly. This model was compared to a method developed by Jan C. Devera in his thesis “Risk Assessment Model for Pipe Rehabilitation and Replacement in a Water Distribution System” (2013), which was also applied to the City of Arroyo Grande’s distribution system. Results provided by this analysis prove that both models are functional due to similar results. The current study utilizes the concepts of random variables and conditional assessment to run various Monte Carlo Simulations as the means of calculating the probability of failure of a pipe. Mr. Devera’s model utilizes simplistic approach that does not involve intensive calculations, but results for both models turned out to be similar when looking at the Arroyo Grande distribution system.
This risk assessment model demonstrates that a risk assessment model can provide a framework to prioritize pipes based on risk. The approach can help create a schedule for a city’s pipe distribution network for maintenance and repair. It is important to note that it is not a predictive model. This study may be employed to better allocate funds for the rehabilitation and replacement of a city’s existing pipe network to promote optimal operating conditions and service to the public.
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Zeng, Wei. "Paired Impulse Response Function and Layer-Peeling Method for Anomaly Detection and Condition Assessment of Pipelines." Thesis, 2020. http://hdl.handle.net/2440/124173.
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Water transmission and distribution pipeline systems are one of society’s most important infrastructure assets. They consist of buried pipes that are often old and deteriorating and their condition is extremely difficult and expensive to determine. This PhD thesis focuses on developing non-invasive and cost-effective methods to both detect anomalies in water pipelines and to assess the condition of pipelines that will allow for predictive repair. The first stage of the research is to identify and localize anomalies in the pipelines. The second stage is to assess the detailed condition of the pipe wall or the size of a blockage if the anomalies in the pipeline are deteriorated sections or blockages. In the thesis, a novel paired impulse response function (termed paired-IRF) technique has been developed for anomaly detection in pressurised pipelines. This is the first time that a transient-based method has been experimentally validated to be able to fully eliminate the effects from background pressure fluctuations and noise. The technique has a high spatial resolution by transferring the anomaly-induced wave reflections into sharp spikes. It has a high detectability by making use of a continuous signal as the injected wave. The continuous wave injection leads to continuous wave reflections and thus provides a large amount of information for signal analysing. The technique can be applied in pipe networks with arbitrary configurations and achieves a wide detection range. The advantages listed above make the technique potentially attractive for field applications. A layer-peeling method has also been developed for condition assessment in pressurised pipelines. The layer-peeling method, which has previously been applied to the inspection of musical instruments and the design of optical fibers, has in this thesis for the first time been applied to water pipelines. It considers the frequency-dependent dissipation and dispersion of the transient waves in the pipeline and enables a bi-directional reconstruction of pipelines with branches. To compensate the cumulative errors which can occur in the layer-peeling method, a fast inverse transient method is developed. To improve the spatial resolution and the tolerance to background pressure fluctuations and noise, the paired-IRF technique has been combined with the layer-peeling method in the thesis. To assist in applying the techniques in the field, a voice-coil-based transient generation system has been developed to generate transient waves and a customized in-pipe optical fiber sensor array has been used for transient pressure measurement. The transient generation and measurement system has been applied in the laboratory and will be used to validate the proposed techniques in the field in the future.Thesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 2020
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Stephens, Mark Leslie. "Transient response analysis for fault detection and pipeline wall condition assessment in field water transmission and distribution pipelines and networks." 2008. http://hdl.handle.net/2440/58241.
Повний текст джерелаАнотація:
Condition assessment of water distribution pipeline assets has been the focus of water authorities for many years. Transient response analysis, including Inverse Transient Analysis (ITA), provides a new potential method for performing specific nondestructive tests that gives much broader information regarding the condition of pipelines than existing technologies. The basic concept involves inducing a transient in a pipeline and measuring its pressure response. The pressure response is theoretically a function of the condition of the pipeline wall (which is the fundamental characteristic related to the propagation of a transient wavefront) and reflections and damping from any fault that may be present. If an accurate transient model of the pipeline under examination can be developed then it may then be possible to isolate particular parameters in it (relating to the wall thickness of the pipeline or faults such as blockages, air pockets and leaks) and fit these to give optimal matches between the model predicted and measured response of the pipeline. This process is often referred to as inverse analysis (and hence the derivation of the name Inverse Transient Analysis). While a significant amount of numerical and laboratory investigation has been carried out focussing on the use of ITA for leak detection, few field studies have been undertaken. The goal of this research is to determine whether transient response analysis and Inverse Transient Analysis (ITA) can be applied in field situations to provide useful information regarding the condition of pipeline walls and the presence of specific faults such as blockages, air pockets and leaks. Numerous field tests are conducted on large scale transmission pipelines, small scale distribution pipelines and a distribution network in order to obtain a view of the nature of the measured transient responses at each scale and to identify any common characteristics. The capacity of existing transient models to replicate the measured responses is then assessed and they are found to be generally incapable of replicating the field data. Given the physical complexity of field pipelines, and a number of complex phenomena that have been traditionally neglected, this result is not unexpected. The research proposes the development of transient models that can be calibrated to measured responses. These models incorporate mechanisms for including mechanical dispersion and damping and follow precedents developed in other fields of engineering in which damping of transient phenomena is significant.http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325427
Thesis (Ph.D.) -- University of Adelaide, School of Civil and Environmental Engineering, 2008
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Stephens, Mark Leslie. "Transient response analysis for fault detection and pipeline wall condition assessment in field water transmission and distribution pipelines and networks." Thesis, 2008. http://hdl.handle.net/2440/58241.
Повний текст джерелаАнотація:
Condition assessment of water distribution pipeline assets has been the focus of water authorities for many years. Transient response analysis, including Inverse Transient Analysis (ITA), provides a new potential method for performing specific nondestructive tests that gives much broader information regarding the condition of pipelines than existing technologies. The basic concept involves inducing a transient in a pipeline and measuring its pressure response. The pressure response is theoretically a function of the condition of the pipeline wall (which is the fundamental characteristic related to the propagation of a transient wavefront) and reflections and damping from any fault that may be present. If an accurate transient model of the pipeline under examination can be developed then it may then be possible to isolate particular parameters in it (relating to the wall thickness of the pipeline or faults such as blockages, air pockets and leaks) and fit these to give optimal matches between the model predicted and measured response of the pipeline. This process is often referred to as inverse analysis (and hence the derivation of the name Inverse Transient Analysis).
While a significant amount of numerical and laboratory investigation has been carried out focussing on the use of ITA for leak detection, few field studies have been undertaken. The goal of this research is to determine whether transient response analysis and Inverse Transient Analysis (ITA) can be applied in field situations to provide useful information regarding the condition of pipeline walls and the presence of specific faults such as blockages, air pockets and leaks. Numerous field tests are conducted on large scale transmission pipelines, small scale distribution pipelines and a distribution network in order to obtain a view of the nature of the measured transient responses at each scale and to identify any common characteristics. The capacity of existing transient models to replicate the measured responses is then assessed and they are found to be generally incapable of replicating the field data. Given the physical complexity of field pipelines, and a number of complex phenomena that have been traditionally neglected, this result is not unexpected. The research proposes the development of transient models that can be calibrated to measured responses. These models incorporate mechanisms for including mechanical dispersion and damping and follow precedents developed in other fields of engineering in which damping of transient phenomena is significant.Thesis (Ph.D.) -- University of Adelaide, School of Civil and Environmental Engineering, 2008
Книги з теми "Pipe condition assessment"
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Marlow, David. Condition assessment of water main appurtenances. Denver, Colo: Water Research Foundation, 2012.
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Yann Le Gouellec De Schwarz. Installation, condition assessment, and reliability of service lines. Denver, Colo: Awwa Research Foundation, 2007.
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Division, Montana Fisheries. [Environmental assessment for a project to relieve low water conditions due to drought at the Jocko River Trout Hatchery, Arlee, Lake County, Montana]. Helena, Mont: The Division, 1994.
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Association, American Water Works. Condition Assessment of Water Mains. American Water Works Association, 2019.
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Kevin, Lillie, and AWWA Research Foundation, eds. Workshop on condition assessment inspection devices for water transmission mains. Denver, Colo: Awwa Research Foundation, 2004.
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Stothard, J. Rheumatoid arthritis of the hand and wrist. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199550647.003.006005.
Повний текст джерелаАнотація:
♦ RA is common♦ Medical treatment is the mainstay and newer anti-TNF drugs are reducing morbidity and thus referral for surgery♦ Assessment is primarily clinical♦ Investigations – Primarily radiographs♦ Treatment• Non-operative• Steroid injections are often very useful• Operative• Site and condition specific♦ In general• DRUJ – excision ulna head• Wrist – partial fusion, arthrodesis, arthroplasty• MP joints – synvestomy, arthroplasty• PIP joints – soft tissue rebalancing, arthrodesis• DIP joints – arthrodesis• Thumb MP and IP joints – arthrodesis
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Virginia. Secretary of Commerce and Trade., Virginia Economic Development Partnership, and Virginia. Dept. of Aviation., eds. Southwest Virginia air freight feasibility study: Report of the Secretary of Commerce and Trade by the Virginia Economic Development Partnership and the Department of Aviation to the Governor and the General Assembly of Virginia. Richmond, Va: Commonwealth of Virginia, 2004.
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Zydroń, Tymoteusz. Wpływ systemów korzeniowych wybranych gatunków drzew na przyrost wytrzymałości gruntu na ścinanie. Publishing House of the University of Agriculture in Krakow, 2019. http://dx.doi.org/10.15576/978-83-66602-46-5.
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The aim of the paper was to determine the influence of root systems of chosen tree species found in the Polish Flysch Carpathians on the increase of soil shear strength (root cohesion) in terms of slope stability. The paper's goal was achieved through comprehensive tests on root systems of eight relatively common in the Polish Flysch Carpathians tree species. The tests that were carried out included field work, laboratory work and analytical calculations. As part of the field work, the root area ratio (A IA) of the roots was determined using the method of profiling the walls of the trench at a distance of about 1.0 m from the tree trunk. The width of the. trenches was about 1.0 m, and their depth depended on the ground conditions and ranged from 0.6 to 1.0 m below the ground level. After preparing the walls of the trench, the profile was divided into vertical layers with a height of 0.1 m, within which root diameters were measured. Roots with diameters from 1 to 10 mm were taken into consideration in root area ratio calculations in accordance with the generally accepted methodology for this type of tests. These measurements were made in Biegnik (silver fir), Ropica Polska (silver birch, black locust) and Szymbark (silver birch, European beech, European hornbeam, silver fir, sycamore maple, Scots pine, European spruce) located near Gorlice (The Low Beskids) in areas with unplanned forest management. In case of each tested tree species the samples of roots were taken, transported to the laboratory and then saturated with water for at least one day. Before testing the samples were obtained from the water and stretched in a. tensile testing machine in order to determine their tensile strength and flexibility. In general, over 2200 root samples were tested. The results of tests on root area ratio of root systems and their tensile strength were used to determine the value of increase in shear strength of the soils, called root cohesion. To this purpose a classic Wu-Waldron calculation model was used as well as two types of bundle models, the so called static model (Fiber Bundle Model — FIRM, FBM2, FBM3) and the deformation model (Root Bundle Model— RBM1, RBM2, mRBM1) that differ in terms of the assumptions concerning the way the tensile force is distributed to the roots as well as the range of parameters taken into account during calculations. The stability analysis of 8 landslides in forest areas of Cicikowicleie and Wignickie Foothills was a form of verification of relevance of the obtained calculation results. The results of tests on root area ratio in the profile showed that, as expected, the number of roots in the soil profile and their ApIA values are very variable. It was shown that the values of the root area ratio of the tested tree species with a diameter 1-10 ram are a maximum of 0.8% close to the surface of the ground and they decrease along with the depth reaching the values at least one order of magnitude lower than close to the surface at the depth 0.5-1.0 m below the ground level. Average values of the root area ratio within the soil profile were from 0.05 to 0.13% adequately for Scots pine and European beech. The measured values of the root area ratio are relatively low in relation to the values of this parameter given in literature, which is probably connected with great cohesiveness of the soils and the fact that there were a lot of rock fragments in the soil, where the tests were carried out. Calculation results of the Gale-Grigal function indicate that a distribution of roots in the soil profile is similar for the tested species, apart from the silver fir from Bie§nik and European hornbeam. Considering the number of roots, their distribution in the soil profile and the root area ratio it appears that — considering slope stability — the root systems of European beech and black locust are the most optimal, which coincides with tests results given in literature. The results of tensile strength tests showed that the roots of the tested tree species have different tensile strength. The roots of European beech and European hornbeam had high tensile strength, whereas the roots of conifers and silver birch in deciduous trees — low. The analysis of test results also showed that the roots of the studied tree species are characterized by high variability of mechanical properties. The values Of shear strength increase are mainly related to the number and size (diameter) of the roots in the soil profile as well as their tensile strength and pullout resistance, although they can also result from the used calculation method (calculation model). The tests showed that the distribution of roots in the soil and their tensile strength are characterized by large variability, which allows the conclusion that using typical geotechnical calculations, which take into consideration the role of root systems is exposed to a high risk of overestimating their influence on the soil reinforcement. hence, while determining or assuming the increase in shear strength of soil reinforced with roots (root cohesion) for design calculations, a conservative (careful) approach that includes the most unfavourable values of this parameter should be used. Tests showed that the values of shear strength increase of the soil reinforced with roots calculated using Wu-Waldron model in extreme cases are three times higher than the values calculated using bundle models. In general, the most conservative calculation results of the shear strength increase were obtained using deformation bundle models: RBM2 (RBMw) or mRBM1. RBM2 model considers the variability of strength characteristics of soils described by Weibull survival function and in most cases gives the lowest values of the shear strength increase, which usually constitute 50% of the values of shear strength increase determined using classic Wu-Waldron model. Whereas the second model (mRBM1.) considers averaged values of roots strength parameters as well as the possibility that two main mechanism of destruction of a root bundle - rupture and pulling out - can occur at the same. time. The values of shear strength increase calculated using this model were the lowest in case of beech and hornbeam roots, which had high tensile strength. It indicates that in the surface part of the profile (down to 0.2 m below the ground level), primarily in case of deciduous trees, the main mechanism of failure of the root bundle will be pulling out. However, this model requires the knowledge of a much greater number of geometrical parameters of roots and geotechnical parameters of soil, and additionally it is very sensitive to input data. Therefore, it seems practical to use the RBM2 model to assess the influence of roots on the soil shear strength increase, and in order to obtain safe results of calculations in the surface part of the profile, the Weibull shape coefficient equal to 1.0 can be assumed. On the other hand, the Wu-Waldron model can be used for the initial assessment of the shear strength increase of soil reinforced with roots in the situation, where the deformation properties of the root system and its interaction with the soil are not considered, although the values of the shear strength increase calculated using this model should be corrected and reduced by half. Test results indicate that in terms of slope stability the root systems of beech and hornbeam have the most favourable properties - their maximum effect of soil reinforcement in the profile to the depth of 0.5 m does not usually exceed 30 kPa, and to the depth of 1 m - 20 kPa. The root systems of conifers have the least impact on the slope reinforcement, usually increasing the soil shear strength by less than 5 kPa. These values coincide to a large extent with the range of shear strength increase obtained from the direct shear test as well as results of stability analysis given in literature and carried out as part of this work. The analysis of the literature indicates that the methods of measuring tree's root systems as well as their interpretation are very different, which often limits the possibilities of comparing test results. This indicates the need to systematize this type of tests and for this purpose a root distribution model (RDM) can be used, which can be integrated with any deformation bundle model (RBM). A combination of these two calculation models allows the range of soil reinforcement around trees to be determined and this information might be used in practice, while planning bioengineering procedures in areas exposed to surface mass movements. The functionality of this solution can be increased by considering the dynamics of plant develop¬ment in the calculations. This, however, requires conducting this type of research in order to obtain more data.
Частини книг з теми "Pipe condition assessment"
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Weeraddana, Dilusha, Harini Hapuarachchi, Lakshitha Kumarapperuma, Nguyen Lu Dang Khoa, and Chen Cai. "Long-Term Water Pipe Condition Assessment: A Semiparametric Model Using Gaussian Process and Survival Analysis." In Advances in Knowledge Discovery and Data Mining, 487–99. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-47436-2_37.
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Yakubovich, A. N., and I. A. Yakubovich. "Assessment of the Pile Foundations Reliability in the Cryolithozone for the Climate Changing Conditions." In Lecture Notes in Civil Engineering, 222–27. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72910-3_32.
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"Pipe Materials: Concrete." In Water Pipeline Condition Assessment, 43–56. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch05.
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"Pipe Materials: Steel." In Water Pipeline Condition Assessment, 57–66. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch06.
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"Pipe Materials: Fiberglass." In Water Pipeline Condition Assessment, 67–77. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch07.
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"Pipe Inspection Tools." In Water Pipeline Condition Assessment, 103–33. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch10.
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"Pipe Materials: Polyvinyl Chloride." In Water Pipeline Condition Assessment, 79–88. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch08.
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"Pipe Materials: Asbestos Cement." In Water Pipeline Condition Assessment, 89–101. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch09.
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"Pipe Materials: Cast Iron and Ductile Iron." In Water Pipeline Condition Assessment, 29–41. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784414750.ch04.
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"Condition Assessment." In Design of Close-Fit Liners for the Rehabilitation of Gravity Pipes, 25–36. Reston, VA: American Society of Civil Engineers, 2021. http://dx.doi.org/10.1061/9780784415801.ch3.
Повний текст джерелаТези доповідей конференцій з теми "Pipe condition assessment"
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Chae, Myung Jin (Andy), Tom Iseley, and Dulcy M. Abraham. "Computerized Sewer Pipe Condition Assessment." In Pipeline Engineering and Construction International Conference 2003. Reston, VA: American Society of Civil Engineers, 2003. http://dx.doi.org/10.1061/40690(2003)12.
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Yan, J. M., and K. Vairavamoorthy. "Fuzzy Approach for Pipe Condition Assessment." In Pipeline Engineering and Construction International Conference 2003. Reston, VA: American Society of Civil Engineers, 2003. http://dx.doi.org/10.1061/40690(2003)11.
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Ékes, Csaba. "Application of Pipe Penetrating Radar for Asbestos Cement Pipe Condition Assessment." In Pipelines 2018. Reston, VA: American Society of Civil Engineers, 2018. http://dx.doi.org/10.1061/9780784481653.020.
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Fisk, Paul S., and John Marshall. "In Situ Strength and Condition Assessment of PCCP Pipe." In Pipelines Specialty Conference 2009. Reston, VA: American Society of Civil Engineers, 2009. http://dx.doi.org/10.1061/41069(360)10.
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Hu, Yafei, Dunling Wang, and Rudaba Chowdhury. "Condition Assessment Methods for AC Pipe and Current Practices." In Pipeline Division Specialty Conference 2010. Reston, VA: American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41138(386)83.
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Corrao, Andi, Brian Briones, Richard VanderSchaaf, and Juan Elli Bermudo. "Condition Assessment Methods for 1920s Lock-Bar Steel Pipe." In Pipelines 2015. Reston, VA: American Society of Civil Engineers, 2015. http://dx.doi.org/10.1061/9780784479360.086.
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Geem, Zong Woo, Chung-Li Tseng, Juhwan Kim, and Cheolho Bae. "Trenchless Water Pipe Condition Assessment Using Artificial Neural Network." In International Conference on Pipeline Engineering and Construction. Reston, VA: American Society of Civil Engineers, 2007. http://dx.doi.org/10.1061/40934(252)26.
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Ékes, Csaba, and Saleem Mahmood. "Looking into the Void: Condition Assessment with Pipe Penetrating Radar." In Pipelines 2019. Reston, VA: American Society of Civil Engineers, 2019. http://dx.doi.org/10.1061/9780784482490.021.
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Engindeniz, Murat, Troy Bontrager, David Zavala, and Paul Murray. "Survey Level Condition Assessment of Bar-Wrapped and Steel Pipe." In Pipelines 2019. Reston, VA: American Society of Civil Engineers, 2019. http://dx.doi.org/10.1061/9780784482490.040.
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Villalobos, Salvador, Richard Stark, and Paul Fisk. "Ultrasonic Measurements for Condition Assessment of Prestressed Concrete Cylinder Pipe." In Pipelines 2019. Reston, VA: American Society of Civil Engineers, 2019. http://dx.doi.org/10.1061/9780784482490.043.
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