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Structural Condition Assessment Of Prestressed Concrete Transit GuidewaysShmerling, Robert Zachary 01 January 2005 (has links)
Objective condition assessment is essential to make better decisions for safety and serviceability of existing civil infrastructure systems. This study explores the condition of an existing transit guideway system that has been in service for thirty-five years. The structural system is composed of six-span continuous prestressed concrete bridge segments. The overall transit system incorporates a number of continuous bridges which share common design details, geometries, and loading conditions. The original analysis is based on certain simplifying assumptions such as rigid behavior over supports and simplified tendon/concrete/steel plate interaction. The current objective is to conduct a representative study for a more accurate understanding of the structural system and its behavior. The scope of the study is to generate finite element models (FEMs) to be used in static and dynamic parameter sensitivity studies, as well load rating and reliability analysis of the structure. The FEMs are used for eigenvalue analysis and simulations. Parameter sensitivity studies consider the effect of changing critical parameters, including material properties, prestress loss, and boundary and continuity conditions, on the static and dynamic structural response. Load ratings are developed using an American Association for State Highway Transportation Officials Load and Resistance Factor Rating (AASHTO LRFR) approach. The reliability of the structural system is evaluated based on the data obtained from various finite element models. Recommendations for experimental validation of the FEM are presented. This study is expected to provide information to make better decisions for operations, maintenance and safety requirements; to be a benchmark for future studies, to establish a procedure and methodology for structural condition assessment, and to contribute to the general research body of knowledge in condition assessment and structural health monitoring.
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Developing a Framework for Selecting Condition Assessment Technologies for Water and Wastewater PipesAgarwal, Manu 17 September 2010 (has links)
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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Effect of Pavement Condition on Traffic Crash Frequency and Severity in VirginiaMohagheghi, Ali 30 September 2020 (has links)
Previous studies show that pavement condition properties are significant factors to enhance road safety and riding experience, and pavements with low quality might have inadequate performance in terms of safety and riding experience. Pavement Management System (PMS) databases include pavement properties for each segment of the road collected by the agencies. Understanding the impact of road characteristics on crash frequency is a key step to prevent crashes. Whereas other studies analyzed the effect of different characteristics such as International Roughness Index (IRI), Rutting Depth (RD), Annual Average Daily Traffic (AADT), this thesis analyzed the effect of Critical Condition Index (CCI) on crash frequency, in addition to the other factors identified in previous studies. Other characteristics such as Percentage of Heavy Vehicles, Road Surface Condition, Road Lighting Condition, and Driver Conditions are taken into the consideration. The scope of the study is the interstate highway system in Fairfax County, Virginia. Negative Binomial, Least Square and Nominal Logistic Models were developed, showing that the CCI value is a significant factor to predict the number of crashes, and that it has different effect for different values of AADT. The result of this study is a substantial step towards developing an integrated transportation control and infrastructure management framework. / Master of Science / Many factors cause crashes in the roads. Although there is a common sense that road characteristics such as asphalt quality are important in terms of road safety, there are few studies that scientifically prove that statement. In addition, asphalt maintenance decisions making process is mainly based on cost benefit optimization, and traffic safety is not considered at the process. The purpose of this study is to analyze crashes and road characteristics related to each crash to understand the effect of those characteristics on crash frequency, and eventually, to build a model to predict the number of crashes at each part of the road. The model can help transportation agencies to have a better understanding in terms of safety consequences of their infrastructure management plans. The scope of this study is the highway interstate system in Northern Virginia. Results suggest that pavement condition has a significant impact on crash frequency.
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Development of Wastewater Collection Network Asset Database, Deterioration Models and Management FrameworkYounis, Rizwan January 2010 (has links)
The dynamics around managing urban infrastructure are changing dramatically. Today’s infrastructure management challenges – in the wake of shrinking coffers and stricter stakeholders’ requirements – include finding better condition assessment tools and prediction models, and effective and intelligent use of hard-earn data to ensure the sustainability of urban infrastructure systems. Wastewater collection networks – an important and critical component of urban infrastructure – have been neglected, and as a result, municipalities in North America and other parts of the world have accrued significant liabilities and infrastructure deficits. To reduce cost of ownership, to cope with heighten accountability, and to provide reliable and sustainable service, these systems need to be managed in an effective and intelligent manner.
The overall objective of this research is to present a new strategic management framework and related tools to support multi-perspective maintenance, rehabilitation and replacement (M, R&R) planning for wastewater collection networks. The principal objectives of this research include:
(1) Developing a comprehensive wastewater collection network asset database consisting of high quality condition assessment data to support the work presented in this thesis, as well as, the future research in this area.
(2) Proposing a framework and related system to aggregate heterogeneous data from municipal wastewater collection networks to develop better understanding of their historical and future performance.
(3) Developing statistical models to understand the deterioration of wastewater pipelines.
(4) To investigate how strategic management principles and theories can be applied to effectively manage wastewater collection networks, and propose a new management framework and related system.
(5) Demonstrating the application of strategic management framework and economic principles along with the proposed deterioration model to develop long-term financial sustainability plans for wastewater collection networks.
A relational database application, WatBAMS (Waterloo Buried Asset Management System), consisting of high quality data from the City of Niagara Falls wastewater collection system is developed. The wastewater pipelines’ inspections were completed using a relatively new Side Scanner and Evaluation Technology camera that has advantages over the traditional Closed Circuit Television cameras. Appropriate quality assurance and quality control procedures were developed and adopted to capture, store and analyze the condition assessment data. To aggregate heterogeneous data from municipal wastewater collection systems, a data integration framework based on data warehousing approach is proposed. A prototype application, BAMS (Buried Asset Management System), based on XML technologies and specifications shows implementation of the proposed framework. Using wastewater pipelines condition assessment data from the City of Niagara Falls wastewater collection network, the limitations of ordinary and binary logistic regression methodologies for deterioration modeling of wastewater pipelines are demonstrated. Two new empirical models based on ordinal regression modeling technique are proposed. A new multi-perspective – that is, operational/technical, social/political, regulatory, and finance – strategic management framework based on modified balanced-scorecard model is developed. The proposed framework is based on the findings of the first Canadian National Asset Management workshop held in Hamilton, Ontario in 2007. The application of balanced-scorecard model along with additional management tools, such as strategy maps, dashboard reports and business intelligence applications, is presented using data from the City of Niagara Falls. Using economic principles and example management scenarios, application of Monte Carlo simulation technique along with the proposed deterioration model is presented to forecast financial requirements for long-term M, R&R plans for wastewater collection networks.
A myriad of asset management systems and frameworks were found for transportation infrastructure. However, to date few efforts have been concentrated on understanding the performance behaviour of wastewater collection systems, and developing effective and intelligent M, R&R strategies. Incomplete inventories, and scarcity and poor quality of existing datasets on wastewater collection systems were found to be critical and limiting issues in conducting research in this field. It was found that the existing deterioration models either violated model assumptions or assumptions could not be verified due to limited and questionable quality data. The degradation of Reinforced Concrete pipes was found to be affected by age, whereas, for Vitrified Clay pipes, the degradation was not age dependent. The results of financial simulation model show that the City of Niagara Falls can save millions of dollars, in the long-term, by following a pro-active M, R&R strategy.
The work presented in this thesis provides an insight into how an effective and intelligent management system can be developed for wastewater collection networks. The proposed framework and related system will lead to the sustainability of wastewater collection networks and assist municipal public works departments to proactively manage their wastewater collection networks.
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Protipovodňová ochrana obce Brantice / Flood protection of the municipality BranticeZahradníková, Lenka January 2019 (has links)
The thesis is concerned with the design of a flood protection for the Brantice municipality, a part of which is an adjustment of the Opava river stream bed, specifically kilometer 77,6554 to 78,7020 and, moreover, a design of a reconstruction of the weir at kilometer 78,340. A capacity assessment of the original stream bed in the built-up area and its surroundings is a part of the thesis, as well as a measure to increase the stream capacity and a design of a boulder chute with a water gate, which replaced the original weir. The program HEC-RAS 4.1.0. was used for the stream capacity calculations.
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Revitalizace vybraného úseku toku Hartmanického potoka / Revitalization of the selected section of river "Hartmanický potok"Samková, Aneta January 2017 (has links)
Diploma thesis deal with revitalization Hartmanice river in district Svitavy. Section of interest is on 0,400 – 1,234 of river km. Part of this thesis is also rating current condition of stream and his vegetation accompaniment. Rating was made on base of reconnaissance terrain, my own measurement and photo documentation. In diploma thesis was design some revitalization steps: stabilization sink with wooden sills and stabilization slopes by using willow fences and similar precautions. There was designed total change of flow trend. Rating of current condition and condition of modified stream was made in software HEC-RAS.
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Design changes to simplify maintenance and condition assessment on a tap changer / Designändringar för att förenkla underhåll och oljeprovtagning av en lindningskopplareFermér, Arvid, Modling, Jakob January 2023 (has links)
This master thesis investigates a redesign for a maintenance tube, used for both sampling and draining transformer oil from a tap changer compartment. With the current design, one can do one or the other of sampling and draining. The effect of this on a transformer site during maintenance means that personnel must bring extra equipment to do the maintenance routine. Along with the extra equipment, it also involves climbing the transformer an extra time to place the equipment for draining. The project aims to address several issues in the context of the product. Redesigning the product to reduce maintenance time, and therefore downtime and electrical outages. Reducing the number of times that the transformer housing needs to be climbed in order to perform maintenance work. This with the purpose of improving working environment for maintenance personnel. With the new design of the maintenance tube, draining and sampling can be done with the same pipe without the need for extra equipment. This is through a mechanism in the tube which allows the personnel to choose whether to drain oil from the bottom of the container or to take oil samples from an area in the tap-changer housing which gives more accurate results. The function of the mechanism can be described in the same way as a pen, where if you push the button, a tube will extract itself and close of the sampling inlets, enabling draining from the bottom. Push the button again and the same tube will retract, allowing you to take samples from the appropriate area again. The new design also adheres to the dimensional requirements needed for the design to fulfil the additional functions the tube has. The project results in a design which would not only fill requirements of functions but also preserves some of the previous parts along with their interfaces. This means that the new design could be installed on current versions of tap-changer models when the next service interval is due.
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Posouzení možností revitalizace vodního toku Osoblaha – úsek II / Assessment of the Possibilities The Revitalization of a Watercourse Osoblaha – reach IIVysloužilová, Lucie January 2015 (has links)
This thesis deals with examining the possibility of revitalizing the watercourse Osoblaha. It flows through the cadastral territories of municipalities Bohušov, Osoblaha and Kašnice u Bohušova. In this thesis there will be proposed a measure to increase biodiversity of the flow. The trough will be loosened in appropriate segments, oxbow lakes and ponds will be designed. Also the bank shelters for fish stock will be suggested. For slope stabilization will be used reinforcement of fresh willow fences. Impermeable shoots or disintegrating oxbow lakes will be projected in the straight sections of the flow.
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Návrh přírodě blízkých opatření na vodním toku Bobrava / Proposal for the nature friendly measures on the river BobravaMláděnka, Jakub January 2019 (has links)
The aim of the diploma thesis is to describe and evaluate in detail the current state of the Bobrava river in the interest section – river kilometer 1,832-5,743. Part of the work is to assess the capacity of the river flow and the objects connected with it and find the class of an actual safety at village Zelesice. The calculation of the flow rate is performed by using the 1D mathematical model HEC-RAS for selected N-year flows. On the basis of the results of the flow rate, it is made the idea of natural freindly flood protection before the value of the 20-year flow. The result is two variants of river basin adjustment, when each one is leading to make Zelesice safer place and to improve the current state of the river Bobrava.
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Studie možností revitalizačních opatření příměstského vodního toku / Study of river restoration measures of suburban watercourseŠebesta, Radek January 2013 (has links)
This diploma thesis deals with the problem of river restoration. Selected watercourse, which was inappropriately technically modified, had been mapped in detail and land use map was compiled. The watercourse was divided into sections, which were described in detail and assessed for suitability for restoration action. The new nature-friendly channel was designed on the selected section of the watercourse. Technical graphic documentation was designed.
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