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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Sistema de gerência de pavimentos aeroportuários: estudo de caso no Aeroporto Estadual de Araraquara / Airport pavement management system: a case study in Araraquara State Airport

Cossío Durán, Jorge Braulio 26 February 2015 (has links)
A presente pesquisa objetiva contribuir para a implantação de Sistemas de Gerência de Pavimentos Aeroportuários (SGPA), tendo por base um estudo de caso desenvolvido no Aeroporto Estadual de Araraquara-SP Bartolomeu de Gusmão. Foi criado um banco de dados informatizado, através do FAA PAVEAIR, programa computacional de gerência de pavimentos aeroportuários disponibilizado pelo FAA (Federal Aviation Administration), que permitiu o armazenamento de toda informação inerente aos pavimentos do complexo aeroportuário e a determinação, com base no método PCI (Pavement Condition Index), da condição atual da pista de pousos e decolagens, da pista de rolagem e do pátio de aeronaves. Os resultados mostraram que o aeroporto de Araraquara apresenta condição regular de operação, indicada por um PCI médio de 67, e que os principais defeitos encontrados foram desagregação das partículas da mistura asfáltica, trincas transversais e, principalmente, trincas longitudinais. Por conseguinte, foram planejadas intervenções de manutenção e reabilitação, de modo a evitar situações que levassem ao comprometimento geral da condição dos pavimentos e, por consequência, a um aumento significativo dos custos de conservação. A melhor estratégia, se aplicada ao longo dos vinte anos de período de projeto, resultaria em um valor de PCI médio igual a 77, correspondente a boas condições de operação. Dessa forma, o estudo de caso desenvolvido contribuiu, com um exemplo completo, para a implantação de um SGPA em nível de rede e, mais ainda, para o desenvolvimento de um SGPA integral para a rede de aeroportos de administrações aeroportuárias de pequeno, médio e grande portes no Brasil, o que deve ser precedido pela elaboração de legislação específica que exija a aplicação efetiva de técnicas de manutenção que prolonguem a vida útil dos pavimentos, especialmente devido ao aumento da demanda por transporte aéreo e à necessidade de modernas e potentes aeronaves, que requerem, cada vez mais, melhores condições funcionais e estruturais das pistas de pousos e decolagens e dos pátios de aeronaves dos aeroportos. / This research aims to contribute to the implementation of Airport Pavements Management Systems (SGPA), based on a case study developed at the Araraquara State Airport Bartolomeu de Gusmao, in the State of Sao Paulo, Brazil. A computerized database was created, using the FAA PAVEAIR, an airport pavement management computer program provided by the FAA (Federal Aviation Administration), which allowed the storage all information inherent to the airport complex facilities and determining, based on the method of PCI (Pavement Condition Index), the current condition of the runway, taxiway and apron. The results showed that the airport presents regular operating condition, indicated by an average PCI of 67, and that the main defects found were raveling, transverse cracks and mainly longitudinal cracks. Therefore, maintenance and rehabilitation operations are planned so as to avoid situations that could lead to impairment of the general condition of the pavement and, consequently, a significant increase of maintenance costs. The best strategy, if applied over the twenty-year project period, would result in average PCI value of 77, corresponding to good operating condition. Thus, the case study developed contributed with a complete example, for the implementation of a SGPA network-level and even more so for the development of a comprehensive SGPA to the airport network of administrations of small, medium and large airports in Brazil, which should be preceded by the enactment of specific legislation that requires the effective application of maintenance techniques that prolong the life of pavements, especially due to increased demand for air transport and the need for modern and powerful aircraft, requiring increasingly, better functional and structural conditions of runways and aprons.
12

Application of an Improved Transition Probability Matrix Based Crack Rating Prediction Methodology in Florida’s Highway Network

Nasseri, Sahand 28 February 2008 (has links)
With the growing need to maintain roadway systems for provision of safety and comfort for travelers, network level decision-making becomes more vital than ever. In order to keep pace with this fast evolving trend, highway authorities must maintain extremely effective databases to keep track of their highway maintenance needs. Florida Department of Transportation (FDOT), as a leader in transportation innovations in the U.S., maintains Pavement Condition Survey (PCS) database of cracking, rutting, and ride information that are updated annually. Crack rating is an important parameter used by FDOT for making maintenance decisions and budget appropriation. By establishing a crack rating threshold below which traveler comfort is not assured, authorities can screen the pavement sections which are in need of Maintenance and Rehabilitation (M&R). Hence, accurate and reliable prediction of crack thresholds is essential to optimize the rehabilitation budget and manpower. Transition Probability Matrices (TPM) can be utilized to accurately predict the deterioration of crack ratings leading to the threshold. Such TPMs are usually developed by historical data or expert or experienced maintenance engineers' opinion. When historical data are used to develop TPMs, deterioration trends have been used vii indiscriminately, i.e. with no discrimination made between pavements that degrade at different rates. However, a more discriminatory method is used in this thesis to develop TPMs based on classifying pavements first into two groups. They are pavements with relatively high traffic and, pavements with a history of excessive degradation due to delayed rehabilitation. The new approach uses a multiple non-linear regression process to separately optimize TPMs for the two groups selected by prior screening of the database. The developed TPMs are shown to have minimal prediction errors with respect to crack ratings in the database that were not used in the TPM formation. It is concluded that the above two groups are statistically different from each other with respect to the rate of cracking. The observed significant differences in the deterioration trends would provide a valuable tool for the authorities in making critical network-level decisions. The same methodology can be applied in other transportation agencies based on the corresponding databases.
13

Σύστημα οικονομικής και περιβαλλοντικής διαχείρισης οδοστρωμάτων με χρήση γενετικών αλγορίθμων

Παναγοπούλου, Μαίρη 31 August 2012 (has links)
Τα τελευταία χρόνια στις περισσότερες χώρες έχει ολοκληρωθεί η κατασκευή οδικών δικτύων και το ενδιαφέρον των φορέων οδοποιίας έχει στραφεί στη διαχείριση των υφιστάμενων οδικών κατασκευών. Το κυριότερο τμήμα της Διαχείρισης Οδικών Δικτύων καταλαμβάνει η Διαχείριση Οδοστρωμάτων. Τα Συστήματα Διαχείρισης Οδοστρωμάτων έχουν ως στόχο την οικονομική διαχείριση των οδοστρωμάτων και χρησιμοποιούν τεχνητή νοημοσύνη για να καταλήξουν στη βέλτιστη και οικονομικά αποδοτικότερη κατανομή των διαθέσιμων πόρων. Το ευφυές σύστημα που διαθέτουν καταφέρνει να εντοπίζει τη βέλτιστη λύση που ελαχιστοποιεί το κόστος συντήρησης αλλά δεν λαμβάνουν υπόψη τους το αντίκτυπο της επιδείνωσης της κατάστασης του οδοστρώματος στο χρήστη και στο περιβάλλον. Στην παρούσα εργασία χρησιμοποιείται ένας γενετικός αλγόριθμος και αναζητείται η βέλτιστη λύση που ελαχιστοποιεί το γενικευμένο κόστος, το οποίο περιλαμβάνει το κόστος συντήρησης, το κόστος του χρήστη εξαιτίας της κατάστασης του οδοστρώματος και το περιβαλλοντικό κόστος. Τα δεδομένα του προβλήματος αφορούν την κατάσταση των τμημάτων που πρόκειται να συντηρηθούν, το είδος της οδού στο οποίο ανήκουν τα τμήματα οδοστρώματος, τα στοιχεία φθορών κάθε τμήματος, τα διαθέσιμα είδη συντήρησης, το ύψος της χρηματοδότησης και τα κυκλοφοριακά χαρακτηριστικά της περιοχής στην οποία βρίσκονται τα υπό συντήρηση τμήματα. Ο αλγόριθμος κατασκευάζει γονίδια επιλέγοντας είδος συντήρησης για κάθε τμήμα και για κάθε χρόνο συμπεριλαμβανομένης και της επιλογής να μην γίνει καμία συντήρηση σε κάποιο χρόνο. Τα γονίδια ελέγχονται με βάση περιορισμούς που έχουν τεθεί από τα μοντέλα φθορών κάθε τμήματος και επιλέγονται να μεταφερθούν στην επόμενη γενιά αυτά που συνδυάζουν το ελάχιστο κόστος και το μέγιστο επίπεδο λειτουργικότητας στο οδόστρωμα. Η διαφορά του μοντέλου σε σχέση με τα κοινά συστήματα διαχείρισης οδοστρωμάτων έγκειται περισσότερο στις υπολογιστικές απαιτήσεις του συστήματος καθώς η εφαρμογή γενετικού αλγορίθμου οδηγεί γρηγορότερα σε λύση από ότι οι κλασικές μέθοδοι βελτιστοποίησης όπως π.χ. ο γραμμικός προγραμματισμός. Η καταλληλότητα και η ευκολία προσαρμογής των γενετικών αλγορίθμων σε προβλήματα διαχείρισης οδοστρωμάτων επαληθεύεται στην παρούσα εργασία. Το σύστημα καταφέρνει να εντοπίζει το βέλτιστο χρόνο με την οικονομικότερη συντήρηση του κάθε τμήματος του οδικού δικτύου και την πιο φιλική λύση για το χρήστη της οδού και το περιβάλλον. / In recent years the focus of the transportation authorities, researchers and practitioners is being shifted from the construction of new roads to the management of existing road structures and especially to road pavements. Pavement Management Systems are widely used and are continuously being improved because they can lead to considerable fund savings and/or to higher levels of service of road pavements. In this work, a model for pavement maintenance and rehabilitation planning and optimal resource allocation is presented. The objective function aims at minimizing a generalized cost parameter which includes a number of monetary cost components and no monetary impacts. In particular, the objective function consists of the following components: (1) agency cost (the cost of applying the selected maintenance and rehabilitation strategy), (2) user costs (they include vehicle operating cost for fuel consumption, vehicle maintenance and depreciation, traffic delay cost, accident cost, discomfort cost, and delay cost due to maintenance works and (3) environmental impact costs due to traffic pollution and noise. The above cost components are considered with regard to the existing pavement condition levels which are represented by the PSI index. Pavement condition deterioration is assessed through deterministic models that have been developed earlier by our team based on expert opinions and fuzzy systems considering pavement related and traffic parameters, i.e., pavement age, pavement strength, pavement construction quality and traffic loads. The maintenance and rehabilitation treatments are considered with regard to their cost and effectiveness characteristics. Besides the pavement condition deterioration functions, other constraints of the model include budgetary availability (total and individually for different highway groups), threshold values for the minimum accepted pavement condition levels (by highway class), desirable pavement condition levels (by highway class), maintenance and rehabilitation treatment applicability and effectiveness, etc. Due to the size and complexity of the problem (non linear functions), a genetic algorithm has been used as an optimization tool. The algorithm forms solutions by considering applicable maintenance treatments at each pavement section and year within the analysis period. Each solution is checked against all constraints to ensure the feasibility of the solution. No feasible solutions are discarded and new solutions are generated until the required offspring solutions are obtained. The optimization runs over several road sections with different traffic and pavement condition characteristics and within a time span of 10 years. The budgetary or the minimum accepted pavement condition constraints can be altered in order to get a Pareto-front set of optimal solutions for a particular application. Preliminary evaluation indicates that the model provides reasonable results in terms of the appropriate selection of maintenance and rehabilitation treatments and the time of application.
14

Sistema de gerência de pavimentos aeroportuários: estudo de caso no Aeroporto Estadual de Araraquara / Airport pavement management system: a case study in Araraquara State Airport

Jorge Braulio Cossío Durán 26 February 2015 (has links)
A presente pesquisa objetiva contribuir para a implantação de Sistemas de Gerência de Pavimentos Aeroportuários (SGPA), tendo por base um estudo de caso desenvolvido no Aeroporto Estadual de Araraquara-SP Bartolomeu de Gusmão. Foi criado um banco de dados informatizado, através do FAA PAVEAIR, programa computacional de gerência de pavimentos aeroportuários disponibilizado pelo FAA (Federal Aviation Administration), que permitiu o armazenamento de toda informação inerente aos pavimentos do complexo aeroportuário e a determinação, com base no método PCI (Pavement Condition Index), da condição atual da pista de pousos e decolagens, da pista de rolagem e do pátio de aeronaves. Os resultados mostraram que o aeroporto de Araraquara apresenta condição regular de operação, indicada por um PCI médio de 67, e que os principais defeitos encontrados foram desagregação das partículas da mistura asfáltica, trincas transversais e, principalmente, trincas longitudinais. Por conseguinte, foram planejadas intervenções de manutenção e reabilitação, de modo a evitar situações que levassem ao comprometimento geral da condição dos pavimentos e, por consequência, a um aumento significativo dos custos de conservação. A melhor estratégia, se aplicada ao longo dos vinte anos de período de projeto, resultaria em um valor de PCI médio igual a 77, correspondente a boas condições de operação. Dessa forma, o estudo de caso desenvolvido contribuiu, com um exemplo completo, para a implantação de um SGPA em nível de rede e, mais ainda, para o desenvolvimento de um SGPA integral para a rede de aeroportos de administrações aeroportuárias de pequeno, médio e grande portes no Brasil, o que deve ser precedido pela elaboração de legislação específica que exija a aplicação efetiva de técnicas de manutenção que prolonguem a vida útil dos pavimentos, especialmente devido ao aumento da demanda por transporte aéreo e à necessidade de modernas e potentes aeronaves, que requerem, cada vez mais, melhores condições funcionais e estruturais das pistas de pousos e decolagens e dos pátios de aeronaves dos aeroportos. / This research aims to contribute to the implementation of Airport Pavements Management Systems (SGPA), based on a case study developed at the Araraquara State Airport Bartolomeu de Gusmao, in the State of Sao Paulo, Brazil. A computerized database was created, using the FAA PAVEAIR, an airport pavement management computer program provided by the FAA (Federal Aviation Administration), which allowed the storage all information inherent to the airport complex facilities and determining, based on the method of PCI (Pavement Condition Index), the current condition of the runway, taxiway and apron. The results showed that the airport presents regular operating condition, indicated by an average PCI of 67, and that the main defects found were raveling, transverse cracks and mainly longitudinal cracks. Therefore, maintenance and rehabilitation operations are planned so as to avoid situations that could lead to impairment of the general condition of the pavement and, consequently, a significant increase of maintenance costs. The best strategy, if applied over the twenty-year project period, would result in average PCI value of 77, corresponding to good operating condition. Thus, the case study developed contributed with a complete example, for the implementation of a SGPA network-level and even more so for the development of a comprehensive SGPA to the airport network of administrations of small, medium and large airports in Brazil, which should be preceded by the enactment of specific legislation that requires the effective application of maintenance techniques that prolong the life of pavements, especially due to increased demand for air transport and the need for modern and powerful aircraft, requiring increasingly, better functional and structural conditions of runways and aprons.
15

Uso dos Sistemas de Informação Geográfica para a integração da gerência de pavimentos urbanos com as atividades das concessionárias de serviços públicos / not available

José Francisco Gómez Pantigoso 27 April 1998 (has links)
Neste trabalho são analisados os Sistemas de Gerência de Pavimentos Urbanos (SGPU) e os Sistemas de lnformação Geográfica (SIG) visando a obtenção de formas com que possam ser aplicados para a compatibilização das atividades de gerência de todas as redes de infra-estrutura pública urbana (pavimento, água, esgoto, telefone, gás, energia elétrica). Desenvolve-se um projeto piloto, utilizando o aplicativo de SIG TransCAD para a gerência de pavimentos sob duas condições: na primeira, através de uma interface com um programa de gerência de pavimentos urbanos já em utilização (URMS, desenvolvido na Universidade do Texas em Austin); na segunda, como plataforma para o desenvolvimento de um novo sistema de gerência de pavimentos, tanto em nível de rede como em nível de projeto. São utilizadas bases de dados para o pavimento e para a rede de água de abastecimento, criadas para a análise de viabilidade da compatibilização da gerência de pavimentos com as atividades de concessionárias de serviços públicos urbanos, a qual confirmou a grande potencialidade do uso dos Sistemas de Informação Geográfica para a gerência integrada e racional da infra-estrutura pública urbana. / This work presents studies about Urban Pavement Management Systems (U-PMS) and Geographic lnformation Systems (GIS) aiming their utilization as a tool for the harmonization of urban infrastructure (pavement, gas, electric power, sewer, water, telephone) maintenance and rehabilitation activities. lt is developed a pilot study using the SIG software called TransCAD for pavement management under two conditions: the first one, through an interface with an already in use pavement management system (URMS, developed at the University of Texas at Austin); the second one, as a framework for the development of a new pavement management system, at network and project levels. Data bases for pavement and water networks are used for analysis of the harmonization of pavement management with other public infrastructure activities, which confirmed the great power of GIS for utilization in a rational and integrated urban infrastructure management system.
16

Aplikovaný systém hospodaření s vozovkou pro silnice II. a III.třídy v Královéhradeckém kraji / Pavement Management System Applied on Roads of 2nd and 3rd class in Region of Hradec Králové

Nowak, Tomáš January 2014 (has links)
Master‘s thesis deals with pavement management system applied on roads of 2nd and 3rd class in region of Hradec Králové. Its task is to collect failures of pavement, evaluate pavement condition and make plans of pavement maintenance and rehabilitation in variants. One of tasks is also to evaluate attitude of pavement management system in regional level, but also to evaluate the contributions and weaknesses of systematic steps and attitude of access of stakeholders.

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