In the U.S., work-related death is an all too familiar occurrence on farms. Tractor overturns continue to be the most frequent cause of these fatalities. Efforts to alter farming’s ranking as one of the most deadly occupations in the country must provide proven strategies for the elimination of these preventable deaths. In the past, efforts to decrease the rate of overturn fatalities and injuries have largely focused onincreasing the proportion of tractors with a rollover protective structure (ROPS). These devices, in combination with seatbelts, are 99% effective in protecting the tractor operator from death or injury. Unfortunately, only 59% of U.S. tractors are currently equipped with ROPS. Due to the relative lack of political willpower to legislate ROPS installation and the less than encouraging response to education and awareness programs to date, it appeared necessary to explore alternative intervention strategies. The over-arching purpose of this thesis project has been to assess the utility of social marketing as a framework for developing effective health and safety interventions in the farm community. However, our specific objectives included; a more thorough understanding of the perceived barriers and motivators that influence farmer’s safety decisions, the design and evaluation of social marketing incentives developed to encourage safe behaviors and the evaluation of a social marketing campaign designed to positively impact farmer’s intentions and readiness to retrofit unsafe tractors. The research was by and large conducted in New York State and supported by grants from the National Institutes of Occupational Safety and Health (NIOSH). Previous research conducted in the New York farm community had indicated that small crop and livestock farmers would be an ideal intervention target for a social marketing tractor overturn intervention as their farms accounted for close to 85% of New York farms which lack or have only one ROPS protected tractor. A qualitative assessment of perceived barriers and motivators regarding retrofitting behaviors was performed with representatives of the small crop and livestock community. Grounded theory analysis of these in-depth interviews revealed several key categories which include: 1) risk becomes “normal”, 2) risk becomes part of a “farming identity”, and 3) risk becomes “cost-effective”. This information was used to design potential intervention incentives, such as toll-free assistance finding and purchasing ROPS, financial rebates, and campaign messages designed to address farmer’s stated concerns. Subsequent research included testing and revising messages and evaluating the effect of the different campaign incentives in a prospective quasirandomized controlled trial conducted in different regions of New York and Pennsylvania. The results indicate that social marketing offers a promising framework for the development of injury or fatality prevention programs in farm communities. Farmers in the social marketing region demonstrated the most significant changes in both behavioral intention and readiness to retrofit compared to farmers from other regions. Data also indicated that social norms strongly influence farmer’s decisions to work safely, as demonstrated by the strong correlations between behavioral intention measures and measures of social norms. As well as providing an assessment of the utility of social marketing as an intervention framework, the thesis provides a cogent example of how behavioral theories can be used in the design and evaluation of intervention programs. Both stages of change theory and the theory of planned behavior proved to be valuable for measuring dispositional and behavioral changes and for finetuning future interventions.

Multi-purpose project requirements lead to construction of large dams. In order to maintain the desired safety level of such dams, comprehensive inspections based on use of a number of precise instruments are needed. The ideal dam instrumentation system should provide time-dependent information about critical parameters so that possible future behavior of the structure can be predicted. New dams are normally equipped with adequate instrumentation systems. Most of the existing dams, however, do not have adequate instruments or current instrumentation systems may not be in good condition. By implementing the modern equipment to existing dams, the uncertainty associated with the impacts of aging or unexpected severe external events will be reduced and possible remedial measures can be taken accordingly. This study summarizes the major causes of dam failures and introduces the instruments to be used to monitor the key parameters of a dam. The concept of the instrument retrofitting to an unmonitored dam is highlighted through a case study. A sample system is proposed for G&ouml / k&ccedil / ekaya Dam, with reference to an investigation of the current condition of the structure. The deficiencies observed during a site visit are listed and the corresponding rehabilitative repair measures are suggested. Finally, different alternatives of a new instrumentation system are introduced and compared in terms of technical and economical aspects.

Η παρούσα Διατριβή Διπλώματος Ειδίκευσης πραγματεύεται το ζήτημα της καμπτικής ενίσχυσης υποστυλωμάτων οπλισμένου σκυροδέματος υφισταμένων κατασκευών. Συγκεκριμένα, διερευνάται η αποτελεσματικότητα μίας νέας μεθόδου ενίσχυσης, η οποία συνίσταται στην επικόλληση υφάσματος ινοπλισμένων πολυμερών στις παρειές του μέλους, η αγκύρωση του οποίου πέραν της κρίσιμης διατομής εξασφαλίζεται με χρήση αγκυρίων μορφής θυσάνου ινών άνθρακα. Επιπλέον, και εξωτερικά των αγκυρίων, εφαρμόζεται τοπικός μανδύας συνθέτων υλικών. Για το σκοπό αυτό, διεξήχθησαν στο Εργαστήριο Μηχανικής και Τεχνολογίας Υλικών του τμήματος Πολιτικών Μηχανικών του Πανεπιστημίου Πατρών συνολικά πέντε πειραματικές δοκιμές επί υποστυλωμάτων πλήρους κλίμακας. Τα χρησιμοποιηθέντα δοκίμια ήταν υποστυλώματα τετραγωνικής διατομής τύπου προβόλου, με ύψος ίσο με το μισό ύψος τυπικού ορόφου, σχεδιασμένα με ανεπαρκείς λεπτομέρειες όπλισης. Ένα εξ αυτών ενισχύθηκε με τοπικό μανδύα στον πόδα του και υπεβλήθη σε δοκιμή ανακυκλιζόμενης πλευρικής μετακίνησης της κορυφής του, με ταυτόχρονη επιβολή σταθερού θλιπτικού αξονικού φορτίου. Στην ίδια ιστορία φόρτισης υπεβλήθησαν τρία ακόμα δοκίμια, ενισχυμένα σύμφωνα με την υπό διερεύνηση μέθοδο, μελετώντας την επιρροή του αριθμού των εφαρμοσθέντων αγκυρίων και της συνολικής ποσότητας των ινών τους στην αποτελεσματικότητα της μεθόδου. Τέλος, ένα δοκίμιο υπεβλήθη σε μονοτονική φόρτιση αυξανομένης πλευρικής μετακίνησης με ταυτόχρονη επιβολή σταθερού θλιπτικού αξονικού φορτίου, με σκοπό τη μελέτη της επίδρασης της ανακύκλισης της φόρτισης στην αποτελεσματικότητα της μεθόδου. Το σύνολο των χρησιμοποιηθέντων συνθέτων υλικών στο πειραματικό πρόγραμμα, συνίστατο από ίνες άνθρακα σε μήτρα εποξειδικής ρητίνης. Η παρούσα εργασία χωρίζεται σε επτά Κεφάλαια. Το πρώτο Κεφάλαιο αποτελεί την εισαγωγή της παρούσης διατριβής. Παρουσιάζονται οι λόγοι που καθιστούν αναγκαία την καμπτική ενίσχυση υποστυλωμάτων σημαντικού μέρους των υφισταμένων κατασκευών οπλισμένου σκυροδέματος, γίνεται σύντομη αναφορά στη χρήση των συνθέτων υλικών στο πεδίο των ενισχύσεων καθώς και στις μηχανικές ιδιότητες αυτών και τέλος γίνεται αναφορά στο αντικείμενο της παρούσης διατριβής. Στο δεύτερο Κεφάλαιο, παρουσιάζεται το θεωρητικό υπόβαθρο της υπό διερεύνηση μεθόδου ενίσχυσης. Στο τρίτο Κεφάλαιο, συνοψίζονται στοιχεία από τη διεθνή βιβλιογραφία, σχετικά με προγενέστερες έρευνες που έχουν λάβει χώρα και που έχουν άμεση σχέση με το αντικείμενο της παρούσης διατριβής. Στο τέταρτο Κεφάλαιο, παρουσιάζεται το πειραματικό πρόγραμμα που έλαβε χώρα, προκειμένου να αξιολογηθεί η αποτελεσματικότητα της υπό διερεύνηση μεθόδου και η επίδραση των διαφόρων παραμέτρων σε αυτήν. Στο πέμπτο Κεφάλαιο, παρουσιάζονται τα αποτελέσματα των διεξαχθέντων πειραματικών δοκιμών. Γίνεται παρουσίαση των πειραματικών αποτελεσμάτων για το σύνολο των δοκιμίων, σε διαγραμματική κατά κανόνα μορφή. Ακολουθεί συγκριτική παρουσίαση της συμπεριφοράς αυτών. Επίσης, γίνεται προσπάθεια, μέσω των πειραματικών καταγραφών, εκτίμησης των μέσων παραμορφώσεων αστοχίας των χρησιμοποιηθέντων αγκυρίων. Στο έκτο Κεφάλαιο, παρουσιάζεται μια προσπάθεια εκτίμησης των μέσων παραμορφώσεων αστοχίας των χρησιμοποιηθέντων αγκυρίων, μέσω των καταγεγραμμένων κατά τις πειραματικές δοκιμές ροπών αντίστασής των δοκιμίων, κάνοντας χρήση ενός υπολογιστικού εργαλείου, το οποίο αναπτύχθηκε από τον ίδιο το συγγράφοντα για το σκοπό αυτό. Τα εξαγχθέντα συμπεράσματα, εν συνεχεία, αξιολογούνται βάσει των πειραματικών καταγραφών. Στο έβδομο Κεφάλαιο, τέλος, το οποίο αποτελεί και τον επίλογο της παρούσης διατριβής, παρουσιάζονται συγκεντρωτικά τα εξαγχθέντα συμπεράσματα και γίνονται προτάσεις για μελλοντική έρευνα. Μέσω των διεξαχθέντων πειραματικών δοκιμών και της επεξεργασίας των αποτελεσμάτων αυτών, κατέστη σαφές πως η υπό διερεύνηση μέθοδος καμπτικής ενίσχυσης υποστυλωμάτων είναι επαρκώς αποτελεσματική, ώστε να αποτελέσει βιώσιμη λύση στο πεδίο των ενισχύσεων, σε περιπτώσεις που απαιτείται αύξηση της καμπτικής αντοχής υποστυλωμάτων χωρίς παράλληλη απαίτηση αύξησης της ικανότητας παραμόρφωσης αυτών, κυρίως λόγω της ευκολίας εφαρμογής της. / This master thesis presents the results of an experimental program aiming to study the behavior of RC columns under simulated seismic loading, strengthened in flexure (of crucial importance in capacity design) using Carbon Composite Anchors. The role of different parameters is examined, mostly by comparison of the lateral load versus displacement response characteristics. With proper design, it seems that column strength enhancement does not develop at the expense of low deformation capacity.

Η παρούσα διατριβή έχει ως θέμα την σεισμική αποτίμηση υφισταμένου τριώροφου δομήματος οπλισμένου σκυροδέματος. Συγκεκριμένα γίνεται έλεγχος των μέτρων επέμβασης για το κτήριο αιθουσών διδασκαλίας του ΤΕΛ Ναυπάκτου. Για τον σκοπό αυτό χρησιμοποιούνται μη-γραμμικές αναλύσεις (στατικές και δυναμικές) με βάση τις αρχές των κανονιστικών κειμένων ΚΑΝ.ΕΠΕ και EC8 για την αποτίμηση και τον ανασχεδιασμό κατασκευών. Στο πρώτο κεφάλαιο γίνεται τεκμηρίωση του υφιστάμενου δομήματος. Δίνονται στοιχεία για την θέση, την γεωμετρία, τις κατασκευαστικές μεθόδους που εφαρμόστηκαν. Δίνονται τα αποτελέσματα των οπτικών και των ενόργανων ελέγχων και προσδιορίζεται η γεωμετρία του φορέα. Στο δεύτερο κεφάλαιο δίνονται οι παραδοχές και οι αρχές με βάση τις οποίες έγινε η εξιδανίκευση του φορέα για την πραγματοποίηση των μη γραμμικών στατικών αναλύσεων. Για τις αναλύσεις χρησιμοποιείται το πακέτο λογισμικού ANSRuop που έχει αναπτυχθεί στο Εργαστήριο Κατασκευών του Τμήματος. Το μοντέλο μονότονης και ανακυκλιζόμενης φόρτισης που χρησιμοποιείται είναι το γνωστό προσομοίωμα Τakeda με εννέα κανόνες υστέρησης. Προσδιορίζονται οι παραδοχές για τον υπολογισμό των διαθέσιμων αντιστάσεων σε όρους παραμορφώσεων και δυνάμεων που υιοθετούνται από τον ΚΑΝΕΠΕ και τον EC8 καθώς και τα κριτήρια που αποδέχεται το κάθε κείμενο για την επιθυμητή στάθμη αποτίμησης και ανασχεδιασμού του φορέα. Ακόμα γίνεται αναφορά στο μοντέλο προσομοίωσης του λικνισμού των θεμελίων για θεώρηση διαφόρων εδαφών. Εν συνεχεία στο τρίτο Κεφάλαιο γίνεται αναφορά στους στόχους σχεδιασμού που θέτει ο κάθε κανονισμός και στις στάθμες επιτελεστικότητας για τον κάθε κανονισμό. Γίνεται παρουσίαση των τεχνητών σεισμικών καταγραφών που λήφθηκαν υπόψη για την πραγματοποίηση των μη γραμμικών δυναμικών αναλύσεων. Οι καταγραφές είναι κανονικοποιημένες πάνω στο φάσμα του EC8 για τύπο εδάφους C που διαφέρει από το φάσμα σχεδιασμού κατά ΕΑΚ για την στάθμη επιτελεστικότητας «Προστασία ζωής και περιουσίας των ενοίκων » μόνο κατά τον εδαφικό συντελεστή S. Ακόμα δίνεται η μεθοδολογία που υιοθετήθηκε για την εκτίμηση της ικανότητας του κτηρίου έναντι των απαιτήσεων που θέτει ο κανονισμός και προτείνεται εναλλακτικά και από τα δύο κείμενα. Στα κεφάλαια 4 και 5 παρουσιάζονται τα αποτελέσματα των μη-γραμμικών αναλύσεων. Συνολικά πραγματοποιήθηκαν 56 μη-γραμμικές στατικές αναλύσεις και 84 μη-γραμμικές δυναμικές. Για τις μη-γραμμικές στατικές αναλύσεις παρουσιάζονται οι καταγραφές τέμνουσας βάσης μετατόπισης κορυφής ενώ τα αποτελέσματα των μη-γραμμικών δυναμικών αναλύσεων δίνονται με την μορφή των μέσων όρων των δεικτών βλάβης. Τέλος στο 6ο κεφάλαιο γίνεται προσπάθεια ερμηνείας των αποτελεσμάτων για τις αναλύσεις πρίν και μετά την δομητική επέμβαση. / The present project deals with a seismic assessment analysis of an existing reinforced concrete building. A fully performance-based procedure is adopted based on the principals of the draft Greek Retrofitting Code and the draft part 3 of the Eurocode 8 : Assessment and retrofitting of Buildings. The method is subjected on an existing building, which has been constructed, during early 70’ s, prior to the principals of the modern codes for earthquake resistant design. The building is located in the area of Nafpaktos. In the first chapter a summary of the characteristics of the existing building is given. Special data concerning the site, the geometry and the construction methods at the time in which the building was constructed. The results of the damage investigation according to the visual and the instrumental inspection are also given. The basic principals according to which the modelling and the non-linear analysis procedures took place is given in the 2nd chapter. For the analysis procedures the program ANSR University of Patras is used which has been developed in the Structural Laboratory of The Civil Engineering Department of the University of Patras. One-component, point-hinge macromodels are used for the RC members, to relate the end-moment to the chord rotation at member ends within each plane of bending. The M-θ relation in monotonic loading is taken bilinear, with a post-yield hardening ratio p computed assuming antisymmetric bending and using empirical expressions according to the Greek Retrofitting Code and Part-3 of the EC8 (according to the selected limit state). The hysteresis rules supplementing the bilinear monotonic M-θ curve are of the modified-Takeda type. Also the monotonic M-θ relation which is used for the modelling of the foundation uplift is given. In the 3rd chapter the performance objectives of the assessment procedure are given according to the appropriate levels of protection for the selected limit state. The synthetic accellerograms which are used for the Nonlinear dynamic procedure are compatible to the EC8 elastic spectrum for type soil C for the limit state of Significant Damage. Moreover the methodology of the determination of the target displacement according to the Annex B of the EC8-part 1 and the draft Greek Retrofitting Code. Finally in chapters 4 and 5 the results of the nonlinear static and dynamic analysis are presented. For the nonlinear static procedures the results are given in terms of base shear vs roof displacement and in terms of Spectral acceleration vs Spectral displacement for the determination of the target displacement. The results of the NonLinear dynamic procedures are given in terms of mean values of the damage index.

Terrorism has become a serious threat in the world, with bomb attacks carried out both inside and outside buildings. There are already many unreinforced masonry buildings in existence, and some of them are historical buildings. However, they do not perform well under blast loading. Aiming on protecting masonry buildings, retrofitting techniques were developed. Some experimental work on studying the effect of retrofitted URM walls has been done in recent years; however, these tests usually cost a significant amount of time and funds. Because of this, numerical simulation has become a good alternative, and can be used to study the behaviour of masonry structures, and predict the outcomes of experimental tests. This project was carried out to find efficient retrofitting technique under blast loading by developing numerical material models. It was based on experimental research of strengthening URM walls by using retrofitting technologies under out-of-plane loading at the University of Adelaide. The numerical models can be applied to study large-scaled structures under static loading, and the research work is then extended to the field of blast loading. Aiming on deriving efficient material models, homogenization technology was introduced to this research. Fifty cases of numerical analysis on masonry basic cell were conducted to derive equivalent orthotropic material properties. To study the increasing capability in strength and ductility of retrofitted URM walls, pull-tests were simulated using interface element model to investigate the bond-slip relationship of FRP plates bonded to masonry blocks. The interface element model was then used to simulate performance of retrofitted URM walls under static loads. The accuracy of the numerical results was verified by comparing with the experimental results from previous tests at the University of Adelaide by Griffith et al. (2007) on unreinforced masonry walls and by Yang (2007) on FRP retrofitted masonry walls. To study the de-bonding behaviours of retrofits bonded to masonry, and find appropriate solution to protect certain masonry walls against blast loading, various retrofitting technologies were examined. The simulation covers explosive impacts of a wide range of impulses. Based on this work, pressure-impulse diagrams for different types of retrofitted URM walls were developed as a design guideline for estimating the blast effect on retrofitted masonry walls. The outcomes of this research will contribute to the development of numerical simulation on modelling retrofitted URM walls, improving the technique for explosion-resistant of masonry buildings, and providing a type of guideline for blast-resistant design. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1349719 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2009

Terrorism has become a serious threat in the world, with bomb attacks carried out both inside and outside buildings. There are already many unreinforced masonry buildings in existence, and some of them are historical buildings. However, they do not perform well under blast loading. Aiming on protecting masonry buildings, retrofitting techniques were developed. Some experimental work on studying the effect of retrofitted URM walls has been done in recent years; however, these tests usually cost a significant amount of time and funds. Because of this, numerical simulation has become a good alternative, and can be used to study the behaviour of masonry structures, and predict the outcomes of experimental tests. This project was carried out to find efficient retrofitting technique under blast loading by developing numerical material models. It was based on experimental research of strengthening URM walls by using retrofitting technologies under out-of-plane loading at the University of Adelaide. The numerical models can be applied to study large-scaled structures under static loading, and the research work is then extended to the field of blast loading. Aiming on deriving efficient material models, homogenization technology was introduced to this research. Fifty cases of numerical analysis on masonry basic cell were conducted to derive equivalent orthotropic material properties. To study the increasing capability in strength and ductility of retrofitted URM walls, pull-tests were simulated using interface element model to investigate the bond-slip relationship of FRP plates bonded to masonry blocks. The interface element model was then used to simulate performance of retrofitted URM walls under static loads. The accuracy of the numerical results was verified by comparing with the experimental results from previous tests at the University of Adelaide by Griffith et al. (2007) on unreinforced masonry walls and by Yang (2007) on FRP retrofitted masonry walls. To study the de-bonding behaviours of retrofits bonded to masonry, and find appropriate solution to protect certain masonry walls against blast loading, various retrofitting technologies were examined. The simulation covers explosive impacts of a wide range of impulses. Based on this work, pressure-impulse diagrams for different types of retrofitted URM walls were developed as a design guideline for estimating the blast effect on retrofitted masonry walls. The outcomes of this research will contribute to the development of numerical simulation on modelling retrofitted URM walls, improving the technique for explosion-resistant of masonry buildings, and providing a type of guideline for blast-resistant design. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1349719 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2009

Terrorism has become a serious threat in the world, with bomb attacks carried out both inside and outside buildings. There are already many unreinforced masonry buildings in existence, and some of them are historical buildings. However, they do not perform well under blast loading. Aiming on protecting masonry buildings, retrofitting techniques were developed. Some experimental work on studying the effect of retrofitted URM walls has been done in recent years; however, these tests usually cost a significant amount of time and funds. Because of this, numerical simulation has become a good alternative, and can be used to study the behaviour of masonry structures, and predict the outcomes of experimental tests. This project was carried out to find efficient retrofitting technique under blast loading by developing numerical material models. It was based on experimental research of strengthening URM walls by using retrofitting technologies under out-of-plane loading at the University of Adelaide. The numerical models can be applied to study large-scaled structures under static loading, and the research work is then extended to the field of blast loading. Aiming on deriving efficient material models, homogenization technology was introduced to this research. Fifty cases of numerical analysis on masonry basic cell were conducted to derive equivalent orthotropic material properties. To study the increasing capability in strength and ductility of retrofitted URM walls, pull-tests were simulated using interface element model to investigate the bond-slip relationship of FRP plates bonded to masonry blocks. The interface element model was then used to simulate performance of retrofitted URM walls under static loads. The accuracy of the numerical results was verified by comparing with the experimental results from previous tests at the University of Adelaide by Griffith et al. (2007) on unreinforced masonry walls and by Yang (2007) on FRP retrofitted masonry walls. To study the de-bonding behaviours of retrofits bonded to masonry, and find appropriate solution to protect certain masonry walls against blast loading, various retrofitting technologies were examined. The simulation covers explosive impacts of a wide range of impulses. Based on this work, pressure-impulse diagrams for different types of retrofitted URM walls were developed as a design guideline for estimating the blast effect on retrofitted masonry walls. The outcomes of this research will contribute to the development of numerical simulation on modelling retrofitted URM walls, improving the technique for explosion-resistant of masonry buildings, and providing a type of guideline for blast-resistant design. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1349719 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2009

Η ενίσχυση πλαισίων οπλισμένου σκυροδέματος με εμφάτνωση από οπλισμένο σκυρόδεμα αποτελεί μια συχνά χρησιμοποιούμενη και αποτελεσματική μέθοδο για την αύξηση της αντοχής και της δυσκαμψίας. Η πειραματική έρευνα μέχρι στιγμής δεν καλύπτει επαρκώς το πεδίο της ενίσχυσης πλαισίων με φάτνωμα από οπλισμένο σκυρόδεμα και αυτό γιατί έχει διεξαχθεί σε μονώροφα και διώροφα πλαίσια, με πάχος φατνώματος αρκετά μικρότερο από το πλάτος των μελών του υφιστάμενου πλαισίου. Αυτό αποτυπώνεται και στο γεγονός ότι ο Ευρωκώδικας 8 – Μέρος 3 δεν αναφέρεται καθόλου στην προσθήκη εμφατνωμένων τοιχωμάτων. Ο Κανονισμός Επεμβάσεων (Καν.Επε) αναφέρεται στη διαστασιολόγηση των τοιχωμάτων αυτών μόνο σε όρους δυνάμεων και δεν παρέχει μέσα για τον υπολογισμό των χαρακτηριστικών τους παραμορφώσεων και της δυσκαμψίας τους. Σκοπός της παρούσας μελέτης είναι η διερεύνηση της απόκρισης πολυώροφων πλαισίων από οπλισμένο σκυρόδεμα, ενισχυόμενων με εμφατνούμενα τοιχώματα. Πραγματοποιήθηκαν υβριδικές δοκιμές σε τρία 4-όροφα πλαίσια οπλισμένου σκυροδέματος ενισχυμένα με φάτνωμα οπλισμένου σκυροδέματος κλίμακας 1:¾. Παράμετροι διερεύνησης αποτελούν τόσο ο οπλισμός του φατνώματος όσο και η σύνδεση του με το περιβάλλον πλαίσιο, για αυτό τον λόγο εξετάζονται δύο τρόποι σύνδεσης του πλαισίου με το φάτνωμα. Από τα πειραματικά αποτελέσματα προκύπτει ότι η σύνδεση για αμφότερους τους τύπους που εξετάστηκαν οδηγεί σε μονολιθική συμπεριφορά του φατνώματος με τα μέλη του περιβάλλοντος πλαισίου. Για την πιστοποίηση των συμπερασμάτων ακολούθησε εκτεταμένη προσπάθεια εκτέλεσης μη-γραμμικών δυναμικών αναλύσεων της απόκρισης των δοκιμίων χρησιμοποιώντας προσομοιώματα αυξανόμενου βαθμού λεπτομέρειας. Η σύγκριση των πειραμάτικών αποτελεσμάτων με εκείνα τον αναλύσεων έδειξαν ικανοποιητική σύγκλιση. Τέλος, με βάση τα παραπάνω προκύπτει ότι οι ιδιότητες του σύνθετου τοιχώματος μπορούν να υπολογιστούν με όσα ισχύουν κατά Καν.Επε. για μονολιθικό τοίχωμα, εφόσον υιοθετηθούν κατάλληλες παραδοχές. / The construction of reinforced concrete infills is a very effective method for retrofitting multi – storey reinforced concrete buildings. The experimental research to date has conducted only at one or two storey specimens with infill thickness considerably smaller than the width of the members of the existing frame. Because of this lack of knowledge, Eurocode 8 - Part 3 does not cover this technique. The Greek code for Structural Interventions (Kan.Epe.) refers to the dimensioning of these walls only in terms of forces and does not provide means for calculating deformation at yielding and ultimate. The purpose of this study is to investigate the response of multi-storey reinforced concrete frames, retrofitted with reinforced concrete infill walls. Three 4-storey reinforced concrete frames infilled with reinforced concrete were tested at 75%-scale via the hybrid testing method. Parameters of investigation are both the reinforcement of the infill and the connection between the surrounding frame and the infill. Two types of connection were examined. The experimental results show that both connection options lead to a close to monolithic behavior of the specimens and to a favourable flexure-controlled energy absorbing mechanism. From the experimental results deformations characteristics at yielding and ultimate were calculated. The magnitude of these deformations are in good agreement with those predicted for a monolithic wall according to Eurocode 8 and Kan.Epe, if one takes into account the reduced fixed end rotation of the wall at the base of each floor due to the epoxy–grouting of the dowels into the frame members. To verify these conclusions nonlinear dynamic analyses were performed with increasing level of detailing. The comparison of experimental results with those of the analysis showed satisfactory convergence.

This research involves the study of the short term loaded behaviour of mechanically degraded reinforced concrete (RC) flexural elements, which are strengthened with fibre reinforced polymer (FRP) composites. The two main objectives have been: (a) to conduct a series of realistic tests, the results of which would be used to establish the design criteria, and (b) to carry out analytical modelling and hence develop a set of suitable design equations. It is expected that this work will contribute towards the establishment of definitive design guidelines for the strengthening of reinforced concrete structures using advanced fibre composites. The experimental study concentrated on the laboratory testing of 30 simply supported, and 4 two-span continuous full size RC beams, which were strengthened by either FRP plates or fabric sheets. The failure modes of these beams, at ultimate limit state, were examined and the influencing factors were identified. A premature and extremely brittle collapse mechanism was found to be the predominant type of failure for beams strengthened with a large area of FRP composites. A modified semi-empirical approach was presented for predicting the failure load of such over strengthened beams. Despite the lack of ductility in fibre composites, it was found that the FRP strengthened members would exhibit acceptable ductile characteristics, if they were designed to be under strengthened. A new design-based methodology for quantifying the deformability of FRP strengthened elements was proposed, and its difference to the conventional concept of ductility was discussed. The available techniques for ductility evaluation of FRP strengthened concrete members were reviewed and a suitable method was recommended for determining ductility level of FRP strengthened members. A non-linear material based analytical model was developed to simulate the flexural behaviour of the strengthened and control beams, the results were seen to match very well. The parametric study provided an insight into the effects of various factors including the mechanical properties and cross sectional area of FRP composites, on the failure modes and ductility characteristics of the strengthened beams. Based on the findings of the experimental and analytical studies, design equations in the BS 8110 format were developed, and design case studies have been carried out. It was concluded that fibre composites could effectively and safely strengthen mechanically degraded reinforced concrete structures if appropriately designed. The modes of failure and the degree of performance enhancement of FRP strengthened beams depend largely on the composite material properties as well as the original strength and stiffness of the RC structure. If the FRP strengthened elements were designed to be under-strengthened, then the premature and brittle failure mode could be prevented and ductile failure mode could be achieved. It was also found that existing steel reinforcement would always yield before the FRP composite reached the ultimate strength. Furthermore, a critical reinforcement ratio, above which FRP strengthening should not be carried out, was defined. It was concluded that FRP strengthening is most suitable for reinforced concrete floor slabs, bridge decks, flanged beams and other relatively lightly reinforced elements. The study also revealed that to avoid a brittle concrete failure, existing doubly reinforced members should not be strengthened by FRP composites.

Orientador: Carlos Alberto Mariotoni / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-12T13:17:33Z (GMT). No. of bitstreams: 1 Borin_FernandoLuders_M.pdf: 5674159 bytes, checksum: 06b685198e7c4437396ce7f2a615662d (MD5) Previous issue date: 2007 / Resumo: Este trabalho tem por objetivo fornecer maiores subsídios tendo em vista a matriz energética brasileira, no que se refere ao planejamento, repotênciação, operação e controle dos sistemas de geração de energia elétrica, de modo a prover meios de otimização mais eficazes, reduzindo os impactos de recursos naturais e econômicos demandados pelo sistema elétrico de geração e transmissão. O uso de técnicas de rotação ajustável já vem sendo empregado com sucesso em vários casos, tanto a nível nacional, quanto a nível internacional. A geração através de sistemas eólicos é o exemplo mais forte neste sentido, superando as expectativas de planejamento em vários casos. Os sistemas eólicos só podem operar por meio de técnicas de rotação ajustável. Contudo, a utilização das técnicas de rotação ajustável, tem muito a contribuir, mediante devidas ponderações, nos mais diversos segmentos de geração de energia. Qualquer que seja o caso, é possível de se obter ganhos consideráveis, no que se refere à otimização dos aproveitamentos energéticos. Dentro deste contexto, o trabalho apresenta um panorama geral das alternativas de geração de energia elétrica, e os possíveis ganhos que o sistema de rotação ajustável pode disponibilizar em cada um destes casos. Inicialmente são abordados aspectos gerais dos sistemas convencionais, de forma a estabelecer parâmetros de comparação. A seguir, aspectos específicos de geração por meios hidráulicos, térmicos, eólicos são abordados. Uma análise referente a sistemas isolados de geração também é apresentada, agregando vantagens adicionais não evidenciadas nos sistemas interligados. Desta forma, espera-se que levando em consideração estas técnicas de rotação ajustável, possam conduzir a investimentos relativos de expansão, reforma e operação do sistema de forma mais racional, minimizando impactos ambientais e sociais, contado ainda com ganhos de eficiência disponibilizados. / Abstract: This work has for objective to supply larger subsidies the head office Brazilian energetics, in what he/she refers to the planning, retrofitting, operation and control of the systems of electric power generation, in way to provide more effective optimization means, reducing the impacts of natural and economical resources disputed by the electric system of generation and transmission. The use of techniques of adjustable speed has already been used with success in several cases, so much at national level, as for international level. The generation through eolic systems is the strongest example in this sense, overcoming the planning expectations in several cases. The eolic systems can only operate through techniques of adjustable rotation. However, the use of the techniques of adjustable speed, has a lot to contribute, by the due considerations in the most several segments of generation of energy. Any that is the case, is possible of obtaining won considerable, in what it refers the optimization of the energy uses. Inside of this context, the work presents a general panorama of the alternatives of electric power generation, and the possible impacts that the system of adjustable speed can make available in each one of these cases. Initially general aspects of the conventional systems are approached, in way to establish comparison parameters. To proceed, specific aspects of generation for means hydraulic, thermal, eolics are approached. An analysis regarding isolated systems of generation is also presented, joining additional advantages no evidenced in the interlinked systems. This way, it is waited that taking into account these techniques of adjustable rotation, they can lead to relative investments of expansion, it reforms and operation of the system in a more rational way, minimizing environmental and social impacts, still counted with won of efficiency made available. / Mestrado / Recursos Hidricos / Mestre em Engenharia Civil