Matching Items (3)
Description
Pipeline infrastructure forms a vital aspect of the United States economy and standard of living. A majority of the current pipeline systems were installed in the early 1900’s and often lack a reliable database reporting the mechanical properties, and information about manufacturing and installation, thereby raising a concern for their safety and integrity. Testing for the aging pipe strength and toughness estimation without interrupting the transmission and operations thus becomes important. The state-of-the-art techniques tend to focus on the single modality deterministic estimation of pipe strength and do not account for inhomogeneity and uncertainties, many others appear to rely on destructive means. These gaps provide an impetus for novel methods to better characterize the pipe material properties. The focus of this study is the design of a Bayesian Network information fusion model for the prediction of accurate probabilistic pipe strength and consequently the maximum allowable operating pressure. A multimodal diagnosis is performed by assessing the mechanical property variation within the pipe in terms of material property measurements, such as microstructure, composition, hardness and other mechanical properties through experimental analysis, which are then integrated with the Bayesian network model that uses a Markov chain Monte Carlo (MCMC) algorithm. Prototype testing is carried out for model verification, validation and demonstration and data training of the model is employed to obtain a more accurate measure of the probabilistic pipe strength. With a view of providing a holistic measure of material performance in service, the fatigue properties of the pipe steel are investigated. The variation in the fatigue crack growth rate (da/dN) along the direction of the pipe wall thickness is studied in relation to the microstructure and the material constants for the crack growth have been reported. A combination of imaging and composition analysis is incorporated to study the fracture surface of the fatigue specimen. Finally, some well-known statistical inference models are employed for prediction of manufacturing process parameters for steel pipelines. The adaptability of the small datasets for the accuracy of the prediction outcomes is discussed and the models are compared for their performance.
ContributorsDahire, Sonam (Author) / Liu, Yongming (Thesis advisor) / Jiao, Yang (Committee member) / Ren, Yi (Committee member) / Arizona State University (Publisher)
Created2018
Description
Horizontal Directional Drilling (HDD) is a growing and expanding trenchless method utilized to install pipelines from 2 to 60 inch diameters for lengths over 10,000 foot. To date, there are not many public documents where direct costs and bid prices incurred by HDD installations are available and analyzed. The objective is to provide a better understanding of the factors affecting the bid prices of these projects. The first section of the thesis analyzes how project parameters such as product diameter, bore length and soil conditions affect the bid price of water and wastewater pipeline installations using HDD. Through multiple linear regressions, the effect of project parameters on bid prices of small, medium and large rigs projects is extracted. The results were further investigated to gain a better understanding of bid factors that influence the relationship between total cost and the project parameters. The second section uses unit cost, based on bid prices, to compare the costs incurred by defined categories. Parameters such as community type, product type, soil conditions, and geographical region were used in the analysis. Furthermore, using average unit cost from 2001 to 2009, HDD project cost trends are briefly analyzed against the main variations of the US economy from the same time horizon by using economic indicators. It was determined that project geometric factors influence more the bid price of small rig projects than large rig projects because external factors including market rates and economic situation have an increasing impact on bid prices when rig size increases. It was observed that bid price variation of HDD projects over years followed the same trend as the US economic variation described by economic indicators.
ContributorsVilfrant, Emmania Claudyne (Author) / Ariaratnam, Samuel T (Thesis advisor) / Lueke, Jason S (Committee member) / Chasey, Allan D (Committee member) / Arizona State University (Publisher)
Created2010
Description
Much of the water and wastewater lines in the United States are nearing the end of their useful life. A significant reinvestment is needed in the upcoming decades to replace or rehabilitate the water and wastewater infrastructure. Currently, the traditional method for delivering water and wastewater pipeline engineering and construction projects is design-bid-build (DBB). The traditional DBB delivery system is a sequential low-integration process and can lead to inefficiencies and adverse relationships between stakeholders. Alternative project delivery methods (APDM) such as Construction Manager at Risk (CMAR) have been introduced to increase stakeholder integration and ultimately enhance project performance. CMAR project performance impacts have been studied in the horizontal and vertical construction industries. However, the performance of CMAR projects in the pipeline engineering and construction industry has not been quantitatively studied.
The dissertation fills this gap in knowledge by performing the first quantitative analysis of CMAR performance on pipeline engineering and construction projects. This study’s two research objectives are:
(1) Develop a CMAR baseline of commonly measured project performance metrics
(2) Statistically compare the cost and schedule performance of CMAR to that of the traditional DBB delivery method
A thorough literature review led to the development of a data collection survey used in conjunction with structured interviews to gather qualitative and quantitative performance data from 66 completed water and wastewater pipeline projects. Performance data analysis was conducted to provide performance benchmarks for CMAR projects and to compare the performance of CMAR and DBB.
This study provides the first CMAR performance benchmark for pipeline engineering and construction projects. The results span across seven metrics in four performance areas (cost, schedule, project change, and communication). Pipeline projects delivered using CMAR have a median cost and schedule growth of -5% and 5.10%, respectively. These results are significantly improved from DBB baseline performance shown in other industries. To verify this, a statistical analysis was done to compare the cost and schedule performance of CMAR to similar DBB pipeline projects. The results show that CMAR pipeline projects are being delivered with 6.5% less cost growth and with 12.5% less schedule growth than similar DBB projects, providing owners with increased certainty when delivering their pipeline projects.
The dissertation fills this gap in knowledge by performing the first quantitative analysis of CMAR performance on pipeline engineering and construction projects. This study’s two research objectives are:
(1) Develop a CMAR baseline of commonly measured project performance metrics
(2) Statistically compare the cost and schedule performance of CMAR to that of the traditional DBB delivery method
A thorough literature review led to the development of a data collection survey used in conjunction with structured interviews to gather qualitative and quantitative performance data from 66 completed water and wastewater pipeline projects. Performance data analysis was conducted to provide performance benchmarks for CMAR projects and to compare the performance of CMAR and DBB.
This study provides the first CMAR performance benchmark for pipeline engineering and construction projects. The results span across seven metrics in four performance areas (cost, schedule, project change, and communication). Pipeline projects delivered using CMAR have a median cost and schedule growth of -5% and 5.10%, respectively. These results are significantly improved from DBB baseline performance shown in other industries. To verify this, a statistical analysis was done to compare the cost and schedule performance of CMAR to similar DBB pipeline projects. The results show that CMAR pipeline projects are being delivered with 6.5% less cost growth and with 12.5% less schedule growth than similar DBB projects, providing owners with increased certainty when delivering their pipeline projects.
ContributorsFrancom, Tober C (Author) / Ariaratnam, Samuel (Thesis advisor) / El Asmar, Mounir (Thesis advisor) / Bearup, Wylie (Committee member) / Arizona State University (Publisher)
Created2015