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Seismic Performance Evaluation And Analysis Of Steel Structures With Semi-rigid ConnectionsOn, Selim 01 June 2004 (has links) (PDF)
At the design stage, column-beam connections of steel structures are assumed as fully rigid or as hinges, and the design is completed with these assumptions. On the other hand, in practice, steel column-beam connections show neither fully rigid nor fully hinge behaviour, and the characteristic behaviour of the connections lies between these two special cases. Performing realistic calculation of these forces and knowing the behaviour of structures close to reality will decrease life and goods losses to the minimum level in a probable of earthquake to be encountered in the future.
  / In this study, seismic performance of 2-D steel frames were evaluated by Capacity Spectrum Method proposed in the ATC 40 document published in 1996. A new computer program was developed in order to define all geometric and loading data and to perform nonlinear analysis of rigid and semi rigid steel frames for which the performances will be evaluated.
In case studies, 3-Floor Steel Frames that have different bay numbers were investigated in various forms according to the rigid and different semi rigid connection types. In addition, the performances these frames for various seismic regions and soil conditions were compared.
According to the results, it was observed that semi rigidly connected frames are under the effect of smaller ground acceleration have greater displacement values. As a consequence of this ductile and energy dissipative response, it was seen that the stresses in the members of frame become considerably small, relative to the stresses in the rigid frames&rsquo / . Furthermore, the performances of semi-rigid frames can be affected negatively beyond such a low rigidity.
Consequently, the most convenient design should be made according to the seismic and soil region where the structure to be constructed by performing the necessary studies on the connection details in order to achieve desired performance, serviceability and optimum member criteria.
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Seismic evaluation and retrofitting of an existing building in Athens using pushover analysisLazaris, Angelos January 2019 (has links)
Earthquakes are one of the biggest problems in civil engineering all over the world. Due to earthquakes, great disasters in cities with collapsed structures and human losses have been caused. More specific, old buildings that have been built based on old regulations and design building codes do not fulfil anymore the new criteria of seismic designing.In this study, an old building has been evaluated for the seismic load in order to decide if there is a need for strengthening it using retrofitting methods. The seismic evaluation is based on Eurocode 8 and after the application of retrofitting techniques the building fulfilled its seismic design criteria. The existing building is a four-storey, concrete structure that has been built in 1970 and is located in Athens (the capital city of Greece). The seismic evaluation is conducted by using the software Seismostruct.Two analyses are performed in order to evaluate the seismic behavior of the building. First, an eigenvalue analysis is conducted before and after retrofitting. By using this analysis the torsional sensitivity of the building has been checked. Then, using pushover analysis, the comparison of the target displacement (expected displacement of the building for the design seismic action) for each limit state and the displacement of the building when the first member of the building reached the corresponding limit state, is presented. Target displacement must not be greater than this displacement in order to ensure the safety of the building. If the comparison shows that target displacement is greater, the weak links in the facility should be identified and the proper retrofitting method should be applied for the improvement of the seismic behavior of the building. Pushover analysis is conducted before and after the application of retrofitting methods.After performing the eigenvalue and pushover analysis of the existing building it was found that the building was torsional sensitive and shear failures occurred in many beams of the structure. Regarding the bending failures, the target displacement was not greater than the displacement of the building when the first member of the building reached any of the corresponding limit states. Therefore the building was safe against bending failures. With the application of X-shaped steel braces in selected frames, the building had higher stiffness and it was not torsional sensitive but shear failures occurred again in many beams. Furthermore, compressive failures occurred in columns that were connected with the steel braces. Finally, with the application of fibre reinforced plastic jacketing in the members that failed in the previous pushover analysis there were no shear or compressive failures. Finally the structure was safe against seismic actions.The application of retrofitting methods improved the seismic behavior of the building and the structure fulfilled the updated regulations of Eurocode 8 regarding seismic design. This project thesis may give rise to further studies and researches concerning seismic retrofitting and seismic damage prevention.
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A Nonlinear Equivalent Frame Model For Displacement Based Analysis Of Unreinforced Brick Masonry BuildingsDemirel, Ismail Ozan 01 December 2010 (has links) (PDF)
Although performance based assessment procedures are mainly developed for reinforced concrete and steel buildings, URM buildings occupy significant portion of building stock in earthquake prone areas of the world as well as in Turkey. Variability of material properties, non-engineered nature of the construction and difficulties in structural analysis of perforated walls make analysis of URM buildings challenging. Despite sophisticated finite element models satisfy the modeling requirements, extensive experimental data for definition of material behavior and high computational resources are needed. Recently, nonlinear equivalent frame models which are developed assigning lumped plastic hinges to isotropic and homogenous equivalent frame elements are used for nonlinear modeling of URM buildings.
The work presented in this thesis is about performance assessment of unreinforced brick masonry buildings in Turkey through nonlinear equivalent frame modeling technique.
Reliability of the proposed model is tested with a reversed cyclic experiment conducted on a full scale, two-story URM building at the University of Pavia and a dynamic shake table test on a half scale, two story URM building at the Ismes Laboratory at Bergamo. Good agreement between numerical and experimental results is found.
Finally, pushover and nonlinear time history analyses of three unreinforced brick masonry buildings which are damaged in 1995 earthquake of Dinar is conducted using the proposed three dimensional nonlinear equivalent model. After displacement demands of the buildings are determined utilizing Turkish Earthquake Code 2007, performance based assessment of the buildings are done.
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Detailed Evaluation Of An Existing Reinforced Concrete Building Damaged Under Its Own WeightBayraktar, Atilla 01 May 2011 (has links) (PDF)
DETAILED EVALUATION OF AN EXISTING REINFORCED CONCRETE BUILDING DAMAGED UNDER ITS OWN WEIGHT
Bayraktar, Atilla
M.Sc., Department of Civil Engineering
Supervisor: Prof. Dr. Ahmet Yakut
May 2011, 130 pages
A significant part of the Turkey&rsquo / s building inventory consists of reinforced concrete frame structures. In addition to that a big part of the existing building inventory in Turkey shows insufficiency in seismic performance damage or failure of structures under their own loads has also been observed.
The failure of Zü / mrü / t Apartment building that occurred in 2004 in Konya and resulted in the death of 92 people brings the necessity of researches on robustness and reserve capacities of the buildings under gravity loading to front.
In the context of this thesis, the event in Konya that has resulted in the crushing of four columns in Dostlar Building Complex is studied. After the occurrence of the event, the building was visited, plans of existing condition were prepared and pre-assessment was performed. Original plans of the building, strength test results of the concrete samples and reinforcement detection results were obtained. The reasons behind the crushing of the columns have been investigated through a series of analyses based on a number of possible hypotheses. After modeling the building in SAP2000 program, demand-capacity ratios are calculated. Nonlinear behavior of the structure is determined by incremental static pushover analysis and the seismic performance of the building is evaluated by nonlinear procedure described in 2007 Turkish Earthquake Code. To determine the nonlinear behavior under gravity loading and collapse mechanism, incremental vertical pushover analysis is performed.
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Σεισμική αποτίμηση και ενίσχυση τριορόφου κτηρίου οπλισμένου σκυροδέματος / Seismic assessment and strengthening of a 3-story reinforced concrete buildingΒουσβούκης, Ιωάννης 14 May 2007 (has links)
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.
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Cost-benefit Analysis For Various Rehabilitation StrategiesCetinceli, Serkan 01 February 2005 (has links) (PDF)
Over the last decade, six major earthquakes that occurred in Turkey dramatically demonstrated the poor performance of the buildings that were designed and constructed far from Turkish seismic code&rsquo / s requirements. The Marmara region, where most of the population and industry is located, is in the active seismic zone. With the rising cost of damages due to earthquakes, the necessity of the cost-benefit analysis for various rehabilitation strategies used in existing buildings has become a major concern for the decision makers who are in the position of making decisions on the building rehabilitation
This study evaluates the performance of two different rehabilitation strategies applied to two five-story reinforced concrete buildings and assesses their cost-benefit
analyses. These buildings were chosen to be representative of the typical residential To carry out the structural analysis of the buildings, three-dimensional models of the buildings were developed using SAP2000 [6]. Two alternative strengthening methods, insertion of reinforced concrete shear walls and application of Carbon Fiber Reinforced Polymers (CFRP) on hallow clay tile infill walls, were used for both of the buildings. While modeling infill walls strengthened with CFRP, two specific modeling attempts proposed by the researchers at Middle East Technical University were used. Pushover analyses were performed to evaluate seismic performance of the buildings. The Life Safety criterion was chosen as the rehabilitation objective. The global and component response acceptability limits were checked and the cost-benefit analysis was performed in order to determine the most attractive rehabilitation alternative.
The results and comparisons given here illustrated that strengthening with shear wall had the most significant improvement on the seismic performance and cost effectiveness of the case study buildings. Outcomes of this study are only applicable to the
buildings employed here and are bound by the assumptions made, approximations used and parameters considered in this study. The findings cannot be generalized for the buildings rehabilitated with CFRP due to lack of the consistent models for CFRP application. More research needs to be conducted to provide solid guidelines and reliable models applicable to the CFRP rehabilitated infill walls.
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Cross-comparison of Non-Linear Seismic Assessment Methods for Unreinforced Masonry Structures in GroningenPeterson, Viktor, Wang, Zihao January 2020 (has links)
A large amount of low-rise unreinforced masonry structures (URM) can be foundin Groningen, the Netherlands. More and more induced earthquakes with shortduration have been detected in this region due to gas exploitation. Local unreinforcedmasonry (URM) buildings were initially not designed for withstanding seismicactions, so that unexpected damage may occur due to their vulnerability, raising insecurityamong residents. Existing low-rise masonry buildings in Groningen can bedivided into different categories based on their characteristics. Two types of residentialmasonry buildings that fulfil the prerequisites for performing non-linear seismicassessment are chosen to be studied in this thesis project, including the terracedhouse and the detached house.The seismic assessment of structures requires the use of both a discretization methodand a seismic assessment method. The discretization method is used to translate themechanical model into a finite element model used for the numerical analysis. Severalmethods have previously shown to be applicable for seismic assessment, but thiswork investigates the implications of using a continuum model (CM) and an equivalentframe model (EFM) approach to discretization in the general-purpose finiteelement package described in DIANA-FEA-BV (2017). The continuum model approachadopted was in a previous work by Schreppers et al. (2017) validated againstexperimental results and is as such deemed representative of the physical behaviourof the mechanical models investigated. An equivalent frame model approach to beused with DIANA is proposed in the work by Nobel (2017). The continuum modelapproach uses continuum elements with a constitutive model developed for the seismicassessment of masonry structures. This constitutive model captures both shearand flexural failure mechanisms. The equivalent frame model approach uses a combinationof numerically integrated beam elements and nodal interfaces, each witha distinct constitutive model, thus decoupling the description of the flexural andshear behaviour. This approach aims to capture the macro-behaviour at the structurallevel. The applicability of the proposed equivalent frame model approach isevaluated by how well it replicates the validated continuum model approach results.The two discretization methods described are evaluated using two types of seismicassessment methods. The first seismic assessment method used consists of first performinga quasi-static non-linear pushover analysis (NLPO) on the model. Thisresults in the pushover curve, which describes the global behaviour of the modelunder an equivalent lateral load based on the fundamental mode shape of the structure.The pushover curve is then used with the N2-method described in EN1998-1iii(2004) to assess at which peak ground acceleration (PGA) that the model reachesthe near-collapse (NC) limit state. The second seismic assessment method consistsof performing dynamic non-linear time-history analyses (NLTH). This method usesrecorded accelerograms to impose the inertial forces. The PGA for the accelerogramwhere the near-collapse limit state is reached is compared to the PGA fromthe use of the N2-method. The applicability of the pushover analysis in conjunctionwith the N2-method is evaluated by how well it replicates the PGA found from thetime-history analyses and by how well it replicates local failure mechanisms.Therefore, the main objectives of this project can be described by the following twoquestions:i. To what extent can the equivalent frame method be applicable as a properdiscretization method for pushover analyses and time-history analyses oflow-rise unreinforced masonry residential buildings in the Groningen region?ii. To what extent can the non-linear pushover method be adopted toassess the seismic behaviour of low-rise unreinforced masonry residentialbuildings in the Groningen region?The applicability of the equivalent frame model showed to vary. For describing localfailure mechanisms its applicability is poor. Further work on connecting the edgepiers to transverse walls is needed. For seismic assessment using the N2-method theapplicability of the equivalent frame model approach is sensible. The conservativedisplacement capacity counteracts the fact that it is worse at describing local unloading,which produced a larger initial equivalent stiffness of the bi-linear curvesin comparison to the continuum model. For seismic assessment using the timehistorysignals, its applicability is possible. While it could show different behaviourin terms of displacement and damping forces, it still showed a similar PGA at thenear-collapse limit state for the cases at hand.The seismic assessment of the terraced and detached houses by the N2-method issimilar to the seismic prediction by applying time-history analyses. However, thereare still some variations in the initial stiffness, force capacity and displacement capacitybetween these two assessment methods due to the assumptions and limitationsin this study. Overall, considering the pros and cons of the quasi-static pushovermethod, it is deemed applicable during the seismic assessment of the unreinforcedmasonry structures in the Groningen area.
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Seismic Strengthening Of A Mid-rise Reinforced Concrete Frame Using Cfrps: An Application From Real LifeTan, Mustafa Tumer 01 May 2009 (has links) (PDF)
SEISMIC STRENGTHENING OF A
MID-RISE REINFORCED CONCRETE FRAME
USING CFRPs: AN APPLICATION FROM REAL LIFE
Tan, Mustafa Tü / mer
M.S., Department Of Civil Engineering
Supervisor: Prof. Dr. Gü / ney Ö / zcebe
Co-Supervisor: Assoc. Prof. Dr. BariS Binici
May 2009, 162 pages
FRP retrofitting allows the utilization of brick infill walls as lateral load resisting elements. This practical retrofit scheme is a strong alternative to strengthen low to mid-rise deficient reinforced concrete (RC) structures in Turkey. The advantages of the FRP applications, to name a few, are the speed of construction and elimination of the need for building evacuation during construction. In this retrofit scheme, infill walls are adopted to the existing frame system by using FRP tension ties anchored the boundary frame using FRP dowels. Results of experiments have previously shown that FRP strengthened infill walls can enhance lateral load carrying capacity and reduce damage by limiting interstory drift deformations. In previous, analytical studies, a detailed mathematical model and a simplified version of the model for compression struts and tension ties was proposed and verified by comparing model estimations with test results.
In this study, an existing 9-storey deficient RC building located in Antakya was chosen to design and apply a hybrid strengthening scheme with FRPs and reduced number of shear walls. Linear elastic analysis procedure was utilized (force based assessment technique) along with the rules of Mode Superposition Method for the reftrofit design. FRP retrofit scheme was employed using the simplified model and design was conducted such that life safety performance criterion is satisfied employing elastic spectrum with 10% probability of exceedance in 50 years according to the Turkish Earthquake Code 2007. Further analytical studies are performed by using Modal Pushover and Nonlinear Time-History Analyses. At the end of these nonlinear analyses, performance check is performed according to Turkish Earthquake Code 2007, using the strains resulting from the sum of yield and plastic rotations at demand in the critical sections.
CFRP retrofitting works started at October 2008 and finished at December 2008 for the building mentioned in this study. Eccentric reinforced concrete shearwall installation is still being undertaken. All construction business is carried out without evacuation of the building occupants. This project is one of the first examples of its kind in Turkey.
Keywords: CFRP, Carbon Fiber Reinforced Polymers, Masonry Infill Walls, Reinforced Concrete Infill Walls, Mid-Rise Deficient Structures, Turkish Earthquake Code 2007, Modal Pushover Analysis, Nonlinear Time History Analysis, Linear Elastic Building Assessment
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Comparación de la vulnerabilidad sísmica de edificios de concreto armado de 35 pisos con núcleo rígido, con amortiguadores de fluido viscoso y disipadores SLB, mediante el análisis modal pushover en la ciudad de Lima / Comparison of the seismic vulnerability of 35-story reinforced concrete buildings with a rigid core, with viscous fluid dampers and SLB dissipators, using pushover modal analysis in Lima cityArita Claros, Luis Humberto, Lezameta Navarro, Rodrigo André 15 January 2021 (has links)
Actualmente en la ciudad de Lima existe un número limitado de edificios de gran altura. Por lo que no existe mucha literatura de este tipo de edificaciones en Perú. Los códigos peruanos se enfocan en edificios de mediana y baja altura. Por ello, se requiere realizar estudios más detallados para analizar y diseñar de forma más adecuada estas edificaciones altas según la realidad del país. En el presente artículo, se desarrollará el análisis modal pushover a 6 tipos de edificaciones de concreto armado de 35 niveles en la ciudad de Lima.
Se plantea 3 modelos de edificación con distinto sistema estructural y con diferentes plantas (cuadrada y rectangular), siendo las áreas de 29m x 29m y 52m x 26m respectivamente. Estos sistemas estructurales son de núcleo rígido y pórticos con sistema de disipación de energía (amortiguadores de fluido viscoso y disipadores SLB) con objetivo de estudiar su comportamiento frente a solicitaciones sísmicas. Estas edificaciones se establecieron en función de los criterios y requerimientos de los códigos vigentes en el país, como también, distribución de la planta de edificaciones comúnmente usadas para oficinas y viviendas.
Se encontró que los periodos naturales oscilan entre 2.6 a 3.3 segundos para edificios de núcleo rígido, se presenta un incremento para los edificios de amortiguamiento viscoso de 4.2 a 5.4 segundos y también para los de dispositivos SLB oscilan en un rango de 3.7 a 4.6 segundos. Se realizó, a su vez, un análisis no lineal estático modal para obtener las curvas de capacidad para cada tipo de edificación, las cuales fueron comparadas con las demandas sísmicas según las provisiones de diseño de la norma peruana sísmica E.030 y un promedio de espectros de registros de aceleraciones de eventos sísmicos severos en Perú y escalados en un rango de 0.2T a 1.5T.
Finalmente, se determinó los puntos de desempeño para cada caso de edificación siguiendo las metodologías del ATC-40 encontrando que los edificios altos con núcleo rígido presentan aproximadamente el doble de rigidez que los edificios con sistema de disipación de energía, como también, presentan poca ductilidad a diferencia con los edificios con disipadores que presentan una larga ductilidad. / Currently in Lima city there is a limited number of high-rise buildings. So, there isn’t much literature on this type of building in Peru. Peruvian codes focus on medium and low-rise buildings. Therefore, more detailed studies are required to analyze and design these tall buildings more appropriately according to the reality of the country. In this thesis, the modal pushover analysis of 6 types of 35-story reinforced concrete buildings in Lima city will be developed.
Three building models with different structural system and with different plan (square and rectangular) are proposed, being their areas of 29m x 29m and 52m x 26m respectively. These structural systems are rigid core and frames with an energy dissipation system (viscous fluid dampers and SLB dissipators) in order to study their behavior against seismic stresses. These buildings were established based on the criteria and requirements of the current codes in the country, as well as, the distribution of the floors of buildings commonly used for offices and homes.
Natural periods were found to range from 2.6 to 3.3 seconds for rigid core buildings, there is an increase for viscous damping buildings from 4.2 to 5.4 seconds and also for SLB devices to range from 3.7 to 4.6 seconds. In turn, a modal static nonlinear analysis was performed to obtain the capacity curves for each type of building, which were compared with the seismic demands according to the design provisions of the Peruvian seismic code E.030 and an average of spectra of acceleration records of severe seismic events in Peru and scaled in a range of 0.2T to 1.5T.
Finally, the performance points for each building case were determined following the ATC-40 methodologies, finding that tall buildings with a rigid core have approximately twice the stiffness of buildings with an energy dissipation system, as well as having low ductility. unlike buildings with dissipators that have long ductility. / Tesis
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Análisis de riesgo sísmico de colegios públicos de San Juan de Miraflores mediante la metodología de Rapid Visual Screening y evaluación del desempeño sísmico con análisis no-lineales del pabellón 780 PreCardenas Angeles, Omar Percy, Farfán Bonett, Aaron Gabriel 16 January 2021 (has links)
Perú se localiza en una zona de alta sismicidad, debido a que se encuentra encima del área de subducción entre la placa tectónica de Nazca y Sudamericana, perteneciente al cinturón de fuego del Pacífico. Perú es un país en vía de desarrollo, por lo que es de suma importancia estar preparados para auxiliar a los miles de damnificados que pueda haber ante un evento sísmico importante. La evaluación del riesgo sísmico de edificaciones esenciales como colegios y hospitales es necesario para trabajos de reforzamiento estructural en este tipo de infraestructura. En el presente artículo científico, se presenta cuán vulnerables son los colegios públicos del distrito de San Juan de Miraflores en la ciudad de Lima ante un evento sísmico. Para ello, se utilizó la metodología de Inspección Visual Rápida del FEMA P-154. Además, se analizó de forma cuantitativa el pabellón 780 Pre, un módulo educativo estandarizado y construido en los años noventa cuya presencia es frecuente en dicho distrito. Para ello, se realizó un análisis no-lineal estático y no-lineal dinámico. Los resultados de la investigación concluyen que la mayoría de las edificaciones educativas presentan una alta vulnerabilidad sísmica y no cumplen con los requerimientos de uso post-sismo como se exige en la norma sismorresistente; así como también se verificó la deficiencia del módulo 780 Pre frente a un sismo severo cuando este fue sometido a los análisis no-lineales. / Peru is located in a high seismicity zone because it is set above the subduction area between the Nazca and South American tectonic plates, both belonging to the Pacific’s Ring of Fire. Being a developing country, it is of utmost importance to be prepared to help the thousands of victims that may be in the face of a major seismic event. The assessment of the seismic vulnerability of essential buildings —such as schools and hospitals— is necessary for structural reinforcement procedures in this type of infrastructure if needed. In this thesis, it is presented how vulnerable are the public schools of the district of San Juan de Miraflores in the city of Lima to a seismic event. For this, the FEMA P-154 Rapid Visual Screening methodology was used. In addition, the “780 Pre” public school building, a standardized educational building built in the 1990s and whose presence is frequent in that district, was analyzed quantitatively. For this, a static nonlinear and dynamic nonlinear analysis were performed. The results of the investigation show that most of the educational buildings present high seismic vulnerability and do not meet the requirements of post-earthquake use as required by the Peruvian seismic design provisions. Also, the deficiency of the 780 Pre building against a severe earthquake when it was subjected to non-linear analyzes was verified. / Tesis
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