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Bridge Life Cycle Cost Optimization : Analysis, Evaluation & Implementation / Bridge LCCSafi, Mohammed January 2009 (has links)
<p>In infrastructure construction projects especially bridge investments, the most critical decisions that significantly affect the whole bridge LCC are the early stages decisions. Clearly, it's more beneficial to correctly choose the optimum bridge than to choose the optimum construction or repair method.</p><p>The ability of a bridge to provide service over time demands appropriate maintenance by the agency. Thus the investment decision should consider not only the initial activity that creates a public good, but also all future activities that will be required to keep that investment available to the public.</p><p>This research is aiming for bridge sustainability, enhance the bridge related decision making, and facilitate the usage of the bridge related feedbacks. The development of a reliable and usable computer tool for bridge LCC & LCA evaluation is the main target.</p><p>Toward the main goal, many steps were fulfilled. A unique integrated Bridge LCC evaluation methodology was developed. Two systematic evaluation ways were developed, one for bridge user cost and one for the bridge aesthetical and cultural value. To put these two systematic ways in practice, two preliminary computer programs were developed for this purpose. Today and future works are focusing on developing methodology and preliminary computer tool for bridge agency cost as well as the bridge LCA evaluation. KTH unique LCC evaluation system will enable the decision makers to correctly choose the optimum bridge in the early stages decision making phases as well as any later on reparation method.</p> / ETSI
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Att värdera en hamnutbyggnad : en översikt av ekonomiska verktyg samt en värdering av föroreningarLindblom, Niklas January 2008 (has links)
<p>När en kommersiell hamn byggs ut fordras omfattande muddringsarbete för att säkerställa ett brukligt djup för sjöfart. Då stora delar av muddermassorna ofta är förorenade av tungmetaller och miljögifter krävs särskilt omhändertagande av dessa. Traditionella omhändertagningsalternativ består av att deponera massorna på särskild avsedd plats på land eller tippa till havs, något som inte tillåts för förorenade sediment. En relativt ny metod är stabilisering/solidifiering (S/S) som innebär att muddermassorna behandlas med ett bindemedel för att sedan kunna användas som fyllnadsmaterial i exempelvis kajkonstruktioner. Dessa alternativ behöver noga vägas mot varandra med hänsyn till ekonomiska och miljömässiga aspekter. Föreliggande studie undersöker ventuella brister i de ekonomiska värderingar som genomförts inför utbyggandet av Oxelösunds hamn. Vidare genomförs en begränsad cost-benefit analys (CBA) för att värdera alternativen utifrån emissionsnivåer till luft och vatten. Resultatet visar att S/S innan nyttiggörande är det samhällsekonomiskt mest attraktiva alternativet.</p> / <p>When a commercial port is expanding its activities there is need for dredging to secure a safe depth for water borne traffic. The sediments are to a large extent contaminated by metals and toxins which calls for certain treatment. Traditionally sediments have either been disposed of at a specific location on land or dumped at sea; the latter is however not permitted by law. A relatively new method is stabilization/solidification (S/S) which means that the sediments are treated using a solidifying agent after which it is possible to use the dredged materials as filling in construction of jetties. These alternatives need to be carefully compared with respect to economical and environmental aspects. This thesis investigates the potential shortcomings of conducted economical evaluations prior to the expansion of Oxelösund port. Further, a limited cost-benefit analysis is conducted to evaluate the alternatives with respect to emissions of contaminants to air and water. The results show that S/S before utilization of the dredged materials is the most attractive alternative from an economical point of view.</p> / STABCON
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Náklady vlastního kapitálu jako měřítko rizik během životního cyklu podniku a trhu / Cost of equity as the measuring instrument of risks during the corporate- and market life cycleKonečný, Zdeněk January 2013 (has links)
This dissertation is focused on relations between corporate life cycle and the structure of entrepreneurial risk, that is measured by cost of equity. Besides the corporate life cycle there is considered also the market life cycle. The research results prove, that there are only little differences in the structure of entrepreneurial risks depending on the corporate life cycle and the market position.
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Avaliação do ciclo de vida ambiental e econômica de sistemas descentralizados de tratamento de esgoto envolvendo wetlands construídos / Environmental and economic life cycle assessment of wastewater treatment systems involving constructed wetlandsResende, Juliana Dalia 01 November 2018 (has links)
Os sistemas de tratamento de esgotos, apesar de possibilitarem a eliminação ou redução de poluentes e substâncias indesejados presentes nas águas residuárias, também ocasionam impactos ambientais. Essa característica deve ser levada em consideração no momento da instalação de uma alternativa tecnológica para o tratamento de esgoto e na proposição de melhorias aos sistemas selecionados. Uma das ferramentas que pode ser utilizada para avaliar o desempenho ambiental de sistemas de tratamento de esgoto é a Avaliação do Ciclo de Vida (ACV), a qual pode ser complementada pela metodologia de Avaliação do Custo do Ciclo de Vida (ACCV), que permite calcular o custo total de um projeto ao longo de seu ciclo de vida. No presente estudo, a ACV e a ACCV foram utilizadas com o objetivo de analisar os potenciais impactos ambientais e custos de diferentes configurações de sistemas pilotos de tratamento de esgoto envolvendo wetlands construídos (WC) com e sem aeração. Foram obtidos também fatores de alocação para as potenciais cargas ambientais do lodo e do efluente do tanque séptico, que possibilitarão a realização de estudos futuros de ACV para alternativas de destinação do lodo de tanques sépticos. A modelagem dos sistemas e os cálculos envolvidos na avaliação dos impactos do ciclo de vida foram realizados mediante o uso do software openLCA v. 1.6.3. Para a avaliação das categorias de impacto de acidificação terrestre, mudança climática, eutrofização aquática de água doce, formação de oxidantes fotoquímicos, ecotoxicidade de água doce e toxicidade humana foi utilizado o método de avaliação de impacto ReCiPe. Foram avaliadas também as categorias de ecotoxicidade e toxicidade humana, utilizando o método USEtox. Nas análises envolvendo um WC aerado a etapa de operação se mostrou com um maior potencial de causar impactos ambientais para todas as categorias de impacto analisadas, com resultados variando entre 63,9% para a categoria de toxicidade humana e 99,8% para a categoria de eutrofização de água doce. Na comparação de materiais utilizados na construção dos sistemas, o potencial de causar impactos ambientais da fibra de vidro foi até 4,7 vezes menor que o potencial de causar impactos ambientais da alvenaria em tijolos para todas as categorias de impacto analisadas. Contudo, a utilização de fibra de vidro ao invés de alvenaria em tijolos apresentou custos mais elevados. O custo do ciclo de vida por m3 de esgoto tratado do sistema envolvendo um WC com aeração mostrou-se cerca de 1,8 vezes menor do que o do sistema sem aeração. Os resultados encontrados trazem contribuições que podem auxiliar na tomada de decisão no que diz respeito à implantação e operação de sistemas de tratamento de esgoto, visando tornar estes mais sustentáveis do ponto de vista econômico e ambiental / Although wastewater treatment systems, allow for the elimination or reduction of pollutants and unwanted substances in wastewater, they also cause environmental impacts. One tool that can evaluate the environmental performance of wastewater treatment systems is Life Cycle Assessment (LCA), which can be complemented by Life Cycle Cost Analysis (LCCA), which calculates the total cost of a project over its entire life cycle. In the present study, the LCA and LCCA were used to analyze the potential environmental impacts and costs of different wastewater treatment pilot plant configurations involving constructed wetlands (CW) with and without aeration. The modeling of the systems and the calculations involved in the assessment of the life cycle impacts were performed using the openLCA v. 1.6.3 software. The impact assessment method used for the impact categories of terrestrial acidification, climate change, freshwater aquatic eutrophication, formation of photochemical oxidants, ecotoxicity and human toxicity was ReCiPe. The categories of ecotoxicity and human toxicity were also evaluated using the USEtox method. In the analyzes involving an aerated CW, the operation stage showed the greatest potential to cause environmental impacts for all impact categories analyzed, with results varying between 63.9% for the category of human toxicity and 99.8% for the category of freshwater eutrophication. The comparison of materials used in the construction of systems has demonstrated that the potential to cause environmental impacts of fiberglass was up to 4.7 times less than the potential to cause environmental impacts of brick masonry for all impact categories analyzed. However, the use of fiberglass instead of masonry in bricks has presented higher costs. The life cycle cost per cubic meter of treated sewage of the system involving a CW with aeration was about 1.8 times smaller than that of the system without aeration. Results can aid in decision making regarding the implementation and operation of wastewater treatment plants, in order to make these systems more sustainable from an economic and environmental point of views
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Avaliação do ciclo de vida ambiental e econômica de sistemas descentralizados de tratamento de esgoto envolvendo wetlands construídos / Environmental and economic life cycle assessment of wastewater treatment systems involving constructed wetlandsJuliana Dalia Resende 01 November 2018 (has links)
Os sistemas de tratamento de esgotos, apesar de possibilitarem a eliminação ou redução de poluentes e substâncias indesejados presentes nas águas residuárias, também ocasionam impactos ambientais. Essa característica deve ser levada em consideração no momento da instalação de uma alternativa tecnológica para o tratamento de esgoto e na proposição de melhorias aos sistemas selecionados. Uma das ferramentas que pode ser utilizada para avaliar o desempenho ambiental de sistemas de tratamento de esgoto é a Avaliação do Ciclo de Vida (ACV), a qual pode ser complementada pela metodologia de Avaliação do Custo do Ciclo de Vida (ACCV), que permite calcular o custo total de um projeto ao longo de seu ciclo de vida. No presente estudo, a ACV e a ACCV foram utilizadas com o objetivo de analisar os potenciais impactos ambientais e custos de diferentes configurações de sistemas pilotos de tratamento de esgoto envolvendo wetlands construídos (WC) com e sem aeração. Foram obtidos também fatores de alocação para as potenciais cargas ambientais do lodo e do efluente do tanque séptico, que possibilitarão a realização de estudos futuros de ACV para alternativas de destinação do lodo de tanques sépticos. A modelagem dos sistemas e os cálculos envolvidos na avaliação dos impactos do ciclo de vida foram realizados mediante o uso do software openLCA v. 1.6.3. Para a avaliação das categorias de impacto de acidificação terrestre, mudança climática, eutrofização aquática de água doce, formação de oxidantes fotoquímicos, ecotoxicidade de água doce e toxicidade humana foi utilizado o método de avaliação de impacto ReCiPe. Foram avaliadas também as categorias de ecotoxicidade e toxicidade humana, utilizando o método USEtox. Nas análises envolvendo um WC aerado a etapa de operação se mostrou com um maior potencial de causar impactos ambientais para todas as categorias de impacto analisadas, com resultados variando entre 63,9% para a categoria de toxicidade humana e 99,8% para a categoria de eutrofização de água doce. Na comparação de materiais utilizados na construção dos sistemas, o potencial de causar impactos ambientais da fibra de vidro foi até 4,7 vezes menor que o potencial de causar impactos ambientais da alvenaria em tijolos para todas as categorias de impacto analisadas. Contudo, a utilização de fibra de vidro ao invés de alvenaria em tijolos apresentou custos mais elevados. O custo do ciclo de vida por m3 de esgoto tratado do sistema envolvendo um WC com aeração mostrou-se cerca de 1,8 vezes menor do que o do sistema sem aeração. Os resultados encontrados trazem contribuições que podem auxiliar na tomada de decisão no que diz respeito à implantação e operação de sistemas de tratamento de esgoto, visando tornar estes mais sustentáveis do ponto de vista econômico e ambiental / Although wastewater treatment systems, allow for the elimination or reduction of pollutants and unwanted substances in wastewater, they also cause environmental impacts. One tool that can evaluate the environmental performance of wastewater treatment systems is Life Cycle Assessment (LCA), which can be complemented by Life Cycle Cost Analysis (LCCA), which calculates the total cost of a project over its entire life cycle. In the present study, the LCA and LCCA were used to analyze the potential environmental impacts and costs of different wastewater treatment pilot plant configurations involving constructed wetlands (CW) with and without aeration. The modeling of the systems and the calculations involved in the assessment of the life cycle impacts were performed using the openLCA v. 1.6.3 software. The impact assessment method used for the impact categories of terrestrial acidification, climate change, freshwater aquatic eutrophication, formation of photochemical oxidants, ecotoxicity and human toxicity was ReCiPe. The categories of ecotoxicity and human toxicity were also evaluated using the USEtox method. In the analyzes involving an aerated CW, the operation stage showed the greatest potential to cause environmental impacts for all impact categories analyzed, with results varying between 63.9% for the category of human toxicity and 99.8% for the category of freshwater eutrophication. The comparison of materials used in the construction of systems has demonstrated that the potential to cause environmental impacts of fiberglass was up to 4.7 times less than the potential to cause environmental impacts of brick masonry for all impact categories analyzed. However, the use of fiberglass instead of masonry in bricks has presented higher costs. The life cycle cost per cubic meter of treated sewage of the system involving a CW with aeration was about 1.8 times smaller than that of the system without aeration. Results can aid in decision making regarding the implementation and operation of wastewater treatment plants, in order to make these systems more sustainable from an economic and environmental point of views
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Development, characterisation and verification of an integrated design tool for a power source of a soya business unit / J.A. BotesBotes, Jan Adriaan January 2007 (has links)
Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2008.
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Road Design for Future Maintenance : Life-cycle Cost Analyses for Road BarriersKarim, Hawzheen January 2011 (has links)
The cost of a road construction over its service life is a function of design, quality of construction as well as maintenance strategies and operations. An optimal life-cycle cost for a road requires evaluations of the above mentioned components. Unfortunately, road designers often neglect a very important aspect, namely, the possibility to perform future maintenance activities. Focus is mainly directed towards other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects. This doctoral thesis presents the results of a research project aimed to increase consideration of road maintenance aspects in the planning and design process. The following subgoals were established: Identify the obstacles that prevent adequate consideration of future maintenance during the road planning and design process; and Examine optimisation of life-cycle costs as an approach towards increased efficiency during the road planning and design process. The research project started with a literature review aimed at evaluating the extent to which maintenance aspects are considered during road planning and design as an improvement potential for maintenance efficiency. Efforts made by road authorities to increase efficiency, especially maintenance efficiency, were evaluated. The results indicated that all the evaluated efforts had one thing in common, namely ignorance of the interrelationship between geometrical road design and maintenance as an effective tool to increase maintenance efficiency. Focus has mainly been on improving operating practises and maintenance procedures. This fact might also explain why some efforts to increase maintenance efficiency have been less successful. An investigation was conducted to identify the problems and difficulties, which obstruct due consideration of maintainability during the road planning and design process. A method called “Change Analysis” was used to analyse data collected during interviews with experts in road design and maintenance. The study indicated a complex combination of problems which result in inadequate consideration of maintenance aspects when planning and designing roads. The identified problems were classified into six categories: insufficient consulting, insufficient knowledge, regulations and specifications without consideration of maintenance aspects, insufficient planning and design activities, inadequate organisation and demands from other authorities. Several urgent needs for changes to eliminate these problems were identified. One of the problems identified in the above mentioned study as an obstacle for due consideration of maintenance aspects during road design was the absence of a model for calculating life-cycle costs for roads. Because of this lack of knowledge, the research project focused on implementing a new approach for calculating and analysing life-cycle costs for roads with emphasis on the relationship between road design and road maintainability. Road barriers were chosen as an example. The ambition is to develop this approach to cover other road components at a later stage. A study was conducted to quantify repair rates for barriers and associated repair costs as one of the major maintenance costs for road barriers. A method called “Case Study Research Method” was used to analyse the effect of several factors on barrier repairs costs, such as barrier type, road type, posted speed and seasonal effect. The analyses were based on documented data associated with 1625 repairs conducted in four different geographical regions in Sweden during 2006. A model for calculation of average repair costs per vehicle kilometres was created. Significant differences in the barrier repair costs were found between the studied barrier types. In another study, the injuries associated with road barrier collisions and the corresponding influencing factors were analysed. The analyses in this study were based on documented data from actual barrier collisions between 2005 and 2008 in Sweden. The result was used to calculate the cost for injuries associated with barrier collisions as a part of the socio-economic cost for road barriers. The results showed significant differences in the number of injuries associated with collisions with different barrier types. To calculate and analyse life-cycle costs for road barriers a new approach was developed based on a method called “Activity-based Life-cycle Costing”. By modelling uncertainties, the presented approach gives a possibility to identify and analyse factors crucial for optimising life-cycle costs. The study showed a great potential to increase road maintenance efficiency through road design. It also showed that road components with low investment costs might not be the best choice when including maintenance and socio-economic aspects. The difficulties and problems faced during the collection of data for calculating life-cycle costs for road barriers indicated a great need for improving current data collecting and archiving procedures. The research focused on Swedish road planning and design. However, the conclusions can be applied to other Nordic countries, where weather conditions and road design practices are similar. The general methodological approaches used in this research project may be applied also to other studies.
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Att värdera en hamnutbyggnad : en översikt av ekonomiska verktyg samt en värdering av föroreningarLindblom, Niklas January 2008 (has links)
När en kommersiell hamn byggs ut fordras omfattande muddringsarbete för att säkerställa ett brukligt djup för sjöfart. Då stora delar av muddermassorna ofta är förorenade av tungmetaller och miljögifter krävs särskilt omhändertagande av dessa. Traditionella omhändertagningsalternativ består av att deponera massorna på särskild avsedd plats på land eller tippa till havs, något som inte tillåts för förorenade sediment. En relativt ny metod är stabilisering/solidifiering (S/S) som innebär att muddermassorna behandlas med ett bindemedel för att sedan kunna användas som fyllnadsmaterial i exempelvis kajkonstruktioner. Dessa alternativ behöver noga vägas mot varandra med hänsyn till ekonomiska och miljömässiga aspekter. Föreliggande studie undersöker ventuella brister i de ekonomiska värderingar som genomförts inför utbyggandet av Oxelösunds hamn. Vidare genomförs en begränsad cost-benefit analys (CBA) för att värdera alternativen utifrån emissionsnivåer till luft och vatten. Resultatet visar att S/S innan nyttiggörande är det samhällsekonomiskt mest attraktiva alternativet. / When a commercial port is expanding its activities there is need for dredging to secure a safe depth for water borne traffic. The sediments are to a large extent contaminated by metals and toxins which calls for certain treatment. Traditionally sediments have either been disposed of at a specific location on land or dumped at sea; the latter is however not permitted by law. A relatively new method is stabilization/solidification (S/S) which means that the sediments are treated using a solidifying agent after which it is possible to use the dredged materials as filling in construction of jetties. These alternatives need to be carefully compared with respect to economical and environmental aspects. This thesis investigates the potential shortcomings of conducted economical evaluations prior to the expansion of Oxelösund port. Further, a limited cost-benefit analysis is conducted to evaluate the alternatives with respect to emissions of contaminants to air and water. The results show that S/S before utilization of the dredged materials is the most attractive alternative from an economical point of view. / STABCON
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Recycled Concrete Aggregate – A Viable Aggregate Source For Concrete PavementsSmith, James Trevor 27 November 2009 (has links)
Virgin aggregate is being used faster than it is being made available creating a foreseeable shortage in the future. Despite this trend, the availability of demolished concrete for use as recycled concrete aggregate (RCA) is increasing. Using this waste concrete as RCA conserves virgin aggregate, reduces the impact on landfills, decreases energy consumption and can provide cost savings. However, there are still many unanswered questions on the beneficial use of RCA in concrete pavements.
This research addresses the many technical and cost-effective concerns regarding the use of RCA in concrete pavements by identifying concrete mixture and proportioning designs suitable for jointed plain concrete pavements; constructing test sections using varying amounts of RCA; monitoring performance through testing, condition surveys and sensor data; modeling RCA pavement performance; and predicting life cycle costs.
The research was carried out as a partnership between the Centre for Pavement and Transportation Technology (CPATT) at the University of Waterloo, the Cement Association of Canada, Dufferin Construction, and the Natural Sciences and Engineering Research Council of Canada.
The literature review provides an overview of sustainability and key performance indicators, the material properties of RCA both as an aggregate and in concrete, concrete mixture and proportioning designs with RCA, performance of existing RCA pavements, and the implementation of RCA highlighting some examples where RCA has been used successfully.
Twelve preliminary mixes were developed using three total cementitious contents amounts of 315 kg/m3, 330 kg/m3, and 345 kg/m3 to determine four suitable mixes with varying coarse RCA contents (0%, 15%, 30% and 50%) to place at the CPATT test track. At 28-days, all of the twelve mixes exceed the 30 MPa design strength.
Four test sections containing 0%, 15%, 30% and 50% coarse RCA were constructed in June 2007. The test sections had identical cross sections consisting of 250 mm portland cement concrete (PCC), 100 mm asphalt-stabilized OGDL and a 450 mm granular base. For each coarse RCA content, one slab was instrumented with six vibrating wire concrete embedment strain gages to measure long-term longitudinal and transverse strain due to environmental changes, two vibrating wire vertical extensometers to monitor slab curling and warping, two vibrating wire inter-panel extensometers to monitor joint movement, and two maturity meters to measure maturity and temperature.
Quality assurance and quality control (QA/QC) testing showed that the mixes containing RCA exhibited similar or improved performance when compared to the conventional concrete for compressive and flexural strength, freeze-thaw durability and coefficient of thermal expansion.
Pavement performance of the four test sections was evaluated using visual surveys following the Ontario Ministry of Transportation’s Manual for Condition rating of Rigid Pavements. Nine pavement evaluations have been performed every two to four months since construction. All test sections are in excellent condition with pavement condition index (PCI) values greater than 85 after two years in-service and approximately three hundred thousand Equivalent Single Axle Loads.
Sensor data from the strain gauges, and vertical and inter-panel extensometers are providing consistent results between the test sections.
Long-term performance modeling using the Mechanistic-Empirical Pavement Design Guide (ME-PDG) showed improved performance with respect to cracked slabs, joint faulting, and pavement roughness as the RCA content increased. Multivariable sensitivity analysis showed that the performance results were sensitive to CTE, unit weight, joint spacing, edge support, surface absorption, and dowel bar diameter.
Life cycle cost analysis (LCCA) illustrated the savings that can be expected using RCA as a replacement aggregate source as the cost of virgin aggregate increase as the sources becomes depleted. Multivariable sensitivity analysis showed that the LCCA results were sensitive to construction costs, discount rate, and maintenance and rehabilitation quantities.
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Parameterized Seismic Reliability Assessment and Life-Cycle Analysis of Aging Highway BridgesGhosh, Jayadipta 16 September 2013 (has links)
The highway bridge infrastructure system within the United States is rapidly deteriorating and a significant percentage of these bridges are approaching the end of their useful service life. Deterioration mechanisms affect the load resisting capacity of critical structural components and render aging highway bridges more vulnerable to earthquakes compared to pristine structures. While past literature has traditionally neglected the simultaneous consideration of seismic and aging threats to highway bridges, a joint fragility assessment framework is needed to evaluate the impact of deterioration mechanisms on bridge vulnerability during earthquakes. This research aims to offer an efficient methodology for accurate estimation of the seismic fragility of aging highway bridges. In addition to aging, which is a predominant threat that affects lifetime seismic reliability, other stressors such as repeated seismic events or simultaneous presence of truck traffic are also incorporated in the seismic fragility analysis.
The impact of deterioration mechanisms on bridge component responses are assessed for a range of exposure conditions following the nonlinear dynamic analysis of three-dimensional high-fidelity finite element aging bridge models. Subsequently, time-dependent fragility curves are developed at the bridge component and system level to assess the probability of structural damage given the earthquake intensity. In addition to highlighting the importance of accounting for deterioration mechanisms, these time-evolving fragility curves are used within an improved seismic loss estimation methodology to aid in efficient channeling of monetary resources for structural retrofit or seismic upgrade. Further, statistical learning methods are employed to derive flexible parameterized fragility models conditioned on earthquake hazard intensity, bridge design parameters, and deterioration affected structural parameters to provide significant improvements over traditional fragility models and aid in efficient estimation of aging bridge vulnerabilities. In order to facilitate bridge management decision making, a methodology is presented to demonstrate the applicability of the proposed multi-dimensional fragility models to estimate the in-situ aging bridge reliabilities with field-measurement data across a transportation network. Finally, this research proposes frameworks to offer guidance to risk analysts regarding the importance of accounting for supplementary threats stemming from multiple seismic shocks along the service life of the bridge structures and the presence of truck traffic atop the bridge deck during earthquake events.
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