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1
Das, Satrajit. "Seismic Design of Vertically Irregular Reinforced Concrete Structures". NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20000820-165307.
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Seismic building codes, such as the Uniform Building Code (UBC) do not allow the equivalent lateral force (ELF) procedure to be used for structures with vertical irregularities. The UBC defines a structure to be irregular based on the ratio of magnitudes of either strength, stiffness, mass, setback or offset of one floor to that of an adjacent floor. The criteria defining the limits of irregularity are somewhat arbitrary, but are introduced in the code to provide unambiguous, enforceable provisions. The purpose of this study is to quantify the definition of irregular structures for four different vertical irregularities - stiffness, strength, mass and nonstructural masonry infills. A total of 87 building structures with interstory stiffness and strength ratios ranging from 0.09 to 1.89 and 0.27 to 1.07, respectively, and mass ratios of 1.0, 2.5, and 5.0 are considered for a detailed parametric study. The lateral force resisting systems (LFRS) considered are special moment resisting frames and shear walls. These LFRS's are designed based on the forces obtained from the equivalent lateral force procedure. An ELF) analysis. Finally, nonlinear dynamic analysis is performed in order to assess the seismic performance of these buildings. The results show that the restrictions on the applicability of the equivalent lateral force procedure are unnecessarily conservative for irregular structures. Most structures considered in this study, designed on the basis of the ELF approach, perform reasonably well. In some cases, however, there is an initiation of an undesirable collapse mechanism. It is recommended that capacity based criteria in the design phase be appropriately used in the vicinity of the irregularity in order to ensure desired performance and behavior.
2
Mola, Elena. "Criteria for the seismic vulnerability reduction of existing irregular reinforced concrete structures". Grenoble INPG, 2007. http://www.theses.fr/2007INPG0019.
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Le travail de recherche décrit est une contribution au développement de outils pour l'évaluation de la vulnérabilité des structures existantes aux événements sismiques et pour la prise de décision quant à la conception de stratégies de renforcement, notamment en cas d'irrégularité. Premièrement, on a clarifié autant que possible les caractéristiques les plus importantes du comportement sismique des structures irrégulières existantes ; deuxièmement, basé sur la leçon apprise de l'analyse des données expérimentales, on a proposé des critères pour réduire la vulnérabilité sismique de cette classe de structures en concevant des interventions efficaces de réhabilitation. Le travail a été largement basé sur l'exploitation des données dérivant d'une campagne expérimentale étendue effectuée dans le cadre du projet de recherche européen 'SPEAR'. Plusieurs moyens ont été employés à cet effet, complétant l'approche expérimentale : realisation d'un modèle numérique aux éléments finis, application des procédures simplifiées d'évaluation sismique, utilisation de l'analyse modale non linéaire de Karhunen-LoeveThe research is a contribution to the development of tools and criteria for the seismic assessment and retrofitting of existing reinforced concrete structures, in particular plan-wise irregular ones. Ln fact, the 'capacity design' method, based on the rationale of the equal displacernent rule and the central role of ductility, and usually employed for the design of new structures, does not automatically extend to existing irregular structures. The work is thoroughly based on a large scale experimental activity carried out in the framework of the EC-funded project SPEAR (Seismic Performance Assessment and Rehabilitation) and consisting of a series of pseudodynamic tests on a full-size plan-wise irregular three storey frame structure, bath in the as-built and in two different retrofitted configurations. Based on the experimental data, the research attempted at first at clarifying the basic features of the seismic response of such structures ; following to that, the proposed criteria for the reduction of their seismic vulnerability and for the design of effective rehabilitation interventions were presented. To this end, the experimental approach was complemented by the numerical one, with the creation of a numerical model into a finite element structural analysis software and the application of the Karhunen-Loeve nonlinear modal analysis method
3
Aldeka, Ayad Basheer. "Seismic response of acceleration-sensitive non-structural components mounted on irregular multi-storey reinforced concrete buildings". Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5858/.
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This research investigates the seismic responses of lightweight acceleration-sensitive non-structural components (NSCs) integrated on irregular multi-storey reinforced concrete (RC) structures designed on different ground types. Dynamic nonlinear finite element analyses of the primary-secondary systems were conducted to provide insight into the seismic response of the NSCs and to evaluate the accuracy of Eurocode 8 (EC8) predictions when the NSCs are attached to the flexible sides along the heights of the primary structures (P-structures). Various sets of natural and artificial earthquake records consisting of 70 accelerograms were utilised. The effects of the plan and vertical mass irregularities were investigated. The NSCs were modelled as vertical cantilevers fixed at their bases with masses on the free ends and varying lengths so as to match the frequencies of the P-structures. A full dynamic interaction is considered between the NSCs and P-structures. The results suggest that the recommendation of the EC8 underestimates the NSCs’ accelerations at the flexible sides of irregular RC P-structures when the NSCs’ periods match those of the P-structures. Consequently, a modification on the existing EC8 design equation is made for the calculation of the maximum acceleration amplification factors of the NSCs taking into account the effects of both the torsion and the maximum seismic capacity of the P-structure.
4
Barja, Rosas Xiomara Mariela, i Cerron Aldahir Edgar Sotomayor. "Influencia de la distribución de TMDs en la respuesta sísmica de estructuras irregulares de concreto armado". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/651960.
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En este trabajo se analiza el control de la respuesta sísmica de edificaciones asimétricas, mediante la incorporación de Amortiguadores de Masa Sintonizada (TMD), evaluando distintas distribuciones de estos dispositivos en el último piso para obtener una alternativa de mejora en la respuesta de la estructura con el fin de controlar los efectos torsionales de los dos primeros modos de vibrar producto de las irregularidades en planta.
Lo anterior se hace usando un modelo computacional de elementos finitos donde la principal variable es la masa participativa del modo torsional siendo esta la primera forma de vibrar y se obtuvo una reducción hasta de 40% de esa variable.This paper analyzes the control of the seismic response of asymmetric buildings, through the incorporation of Tuned Mass Damper (TMD), evaluating different distributions of these devices on the top floor to obtain an alternative to improve the response of the structure in order to control the torsional effects of the first two mode of vibrating due to irregularities in the plant. The previous one is done using a finite element computational model where the main variable is the participatory mass of the torsional mode, this being the first way to vibrate and a reduction of up to 40% of that variable was obtained.
Trabajo de investigación
5
Hertanto, Eric. "Seismic Assessment of Pre-1970s Reinforced Concrete Structure". Thesis, University of Canterbury. Civil Engineering, 2005. http://hdl.handle.net/10092/1120.
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Reinforced concrete structures designed in pre-1970s are vulnerable under earthquakes due to lack of seismic detailing to provide adequate ductility. Typical deficiencies of pre-1970s reinforced concrete structures are (a) use of plain bars as longitudinal reinforcement, (b) inadequate anchorage of beam longitudinal reinforcement in the column (particularly exterior column), (c) lack of joint transverse reinforcement if any, (d) lapped splices located just above joint, and (e) low concrete strength. Furthermore, the use of infill walls is a controversial issue because it can help to provide additional stiffness to the structure on the positive side and on the negative side it can increase the possibility of soft-storey mechanisms if it is distributed irregularly. Experimental research to investigate the possible seismic behaviour of pre-1970s reinforced concrete structures have been carried out in the past. However, there is still an absence of experimental tests on the 3-D response of existing beam-column joints under bi-directional cyclic loading, such as corner joints. As part of the research work herein presented, a series of experimental tests on beam-column subassemblies with typical detailing of pre-1970s buildings has been carried out to investigate the behaviour of existing reinforced concrete structures. Six two-third scale plane frame exterior beam-column joint subassemblies were constructed and tested under quasi-static cyclic loading in the Structural Laboratory of the University of Canterbury. The reinforcement detailing and beam dimension were varied to investigate their effect on the seismic behaviour. Four specimens were conventional deep beam-column joint, with two of them using deformed longitudinal bars and beam bars bent in to the joint and the two others using plain round longitudinal bars and beam bars with end hooks. The other two specimens were shallow beam-column joint, one with deformed longitudinal bars and beam bars bent in to the joint, the other with plain round longitudinal bars and beam bars with end hooks. All units had one transverse reinforcement in the joint. The results of the experimental tests indicated that conventional exterior beam-column joint with typical detailing of pre-1970s building would experience serious diagonal tension cracking in the joint panel under earthquake. The use of plain round bars with end hooks for beam longitudinal reinforcement results in more severe damage in the joint core when compared to the use of deformed bars for beam longitudinal reinforcement bent in to the joint, due to the combination of bar slips and concrete crushing. One interesting outcome is that the use of shallow beam in the exterior beam-column joint could avoid the joint cracking due to the beam size although the strength provided lower when compared with the use of deep beam with equal moment capacity. Therefore, taking into account the low strength and stiffness, shallow beam can be reintroduced as an alternative solution in design process. In addition, the presence of single transverse reinforcement in the joint core can provide additional confinement after the first crack occurred, thus delaying the strength degradation of the structure. Three two-third scale space frame corner beam-column joint subassemblies were also constructed to investigate the biaxial loading effect. Two specimens were deep-deep beam-corner column joint specimens and the other one was deep-shallow beam-corner column joint specimen. One deep-deep beam-corner column joint specimen was not using any transverse reinforcement in the joint core while the two other specimens were using one transverse reinforcement in the joint core. Plain round longitudinal bars were used for all units with hook anchorage for the beam bars. Results from the tests confirmed the evidences from earthquake damage observations with the exterior 3-D (corner) beam-column joint subjected to biaxial loading would have less strength and suffer higher damage in the joint area under earthquake. Furthermore, the joint shear relation in the two directions is calibrated from the results to provide better analysis. An analytical model was used to simulate the seismic behaviour of the joints with the help of Ruaumoko software. Alternative strength degradation curves corresponding to different reinforcement detailing of beam-column joint unit were proposed based on the test results.
6
Starczewski, Jerzy Andrzej. "Felix Candela : the structure and form of reinforced concrete shells". Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/22954.
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Harry, Ofonime Akpan. "Behaviour of reinforced concrete frame structure against progressive collapse". Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/29623.
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A structure subjected to extreme load due to explosion or human error may lead to progressive collapse. One of the direct methods specified by design guidelines for assessing progressive collapse is the Alternate Load Path method which involves removal of a structural member and analysing the structure to assess its potential of bridging over the removed member without collapse. The use of this method in assessing progressive collapse therefore requires that the vertical load resistance function of the bridging beam assembly, which for a typical laterally restrained reinforced concrete (RC) beams include flexural, compressive arching action and catenary action, be accurately predicted. In this thesis, a comprehensive study on a reliable prediction of the resistance function for the bridging RC beam assemblies is conducted, with a particular focus on a) the arching effect, and b) the catenary effect considering strength degradations. A critical analysis of the effect of axial restraint, flexural reinforcement ratio and span-depth ratio on compressive arching action are evaluated in quantitative terms. A more detailed theoretical model for the prediction of load-displacement behaviour of RC beam assemblies within the compressive arching response regime is presented. The proposed model takes into account the compounding effect of bending and arching from both the deformation and force points of view. Comparisons with experimental results show good agreement. Following the compressive arching action, catenary action can develop at a much larger displacement regime, and this action could help address collapse. A complete resistance function should adequately account for the catenary action as well as the arching effect. To this end, a generic catenary model which takes into consideration the strength degradation due to local failure events (e.g. rupture of bottom rebar or fracture of a steel weld) and the eventual failure limit is proposed. The application of the model in predicting the resistance function in beam assemblies with strength degradations is discussed. The validity of the proposed model is checked against predictions from finite element model and experimental tests. The result indicate that strength degradation can be accurately captured by the model. Finally, the above developed model framework is employed in investigative studies to demonstrate the application of the resistance functions in a dynamic analysis procedure, as well as the significance of the compressive arching effect and the catenary action in the progressive collapse resistance in different designs. The importance of an accurate prediction of the arching effect and the limiting displacement for the catenary action is highlighted.
8
De, Rose David. "The rehabilitation of a concrete structure using fibre reinforced plastics". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29388.pdf.
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Stančík, Adam. "Mateřská škola v Novém Jičíně". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227500.
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Single-storey C-shaped building of kindergarten in Nový Jičín with flat green roof.The building is situated on the flat land. The plot is accessible by local road. Kindergarted has irregular plan. The ends are connected by connecting tunnel, which is partly below ground level. Courtyard facade is a vertical garden - green facade.
10
Zhao, Li. "SPATIAL RELIABILITY ANALYSIS FOR CORRODED REINFORCED CONCRETE STRUCTURES". University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1479123930240399.
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Bai, Jong-Wha. "Seismic fragility and retrofitting for a reinforced concrete flat-slab structure". Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/521.
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The effectiveness of seismic retrofitting applied to enhance seismic performance was assessed for a five-story reinforced concrete (RC) flat-slab building structure in the central United States. In addition to this, an assessment of seismic fragility that relates the probability of exceeding a performance level to the earthquake intensity was conducted. The response of the structure was predicted using nonlinear static and dynamic analyses with synthetic ground motion records for the central U.S. region. In addition, two analytical approaches for nonlinear response analysis were compared. FEMA 356 (ASCE 2000) criteria were used to evaluate the seismic performance of the case study building. Two approaches of FEMA 356 were used for seismic evaluation: global-level and member-level using three performance levels (Immediate Occupancy, Life Safety and Collapse Prevention). In addition to these limit states, punching shear drift limits were also considered to establish an upper bound drift capacity limit for collapse prevention. Based on the seismic evaluation results, three possible retrofit techniques were applied to improve the seismic performance of the structure, including addition of shear walls, addition of RC column jackets, and confinement of the column plastic hinge zones using externally bonded steel plates. Finally, fragility relationships were developed for the existing and retrofitted structure using several performance levels. Fragility curves for the retrofitted structure were compared with those for the unretrofitted structure. For various performance levels to assess the fragility curves, FEMA global drift limits were compared with the drift limits based on the FEMA member-level criteria. In addition to this, performance levels which were based on additional quantitative limits were also considered and compared with FEMA drift limits.
12
Irving, Jonathan. "Soil structure interaction of fibre reinforced concrete floor slabs on grade". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0016/MQ54627.pdf.
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Ouyang, Yi, i 欧阳禕. "Theoretical study of hybrid masonry : RC structure behaviour under lateral earthquake loading". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/196090.
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A confined masonry (CM) wall consists of a masonry wall panel surrounded by reinforced concrete (RC) members on its perimeters. Low-rise CM structures are widely used in earthquake-risked (EQ-risked) rural or suburban areas all over the world. Most of these structures fail in shear pattern under lateral EQ loads, and some of them collapse under a severe or even a moderate EQ due to inappropriate design. On the other hand, buildings constructed of RC frames have much better performance in resisting EQs, since their RC members have larger dimensions and heavier reinforcing ratios than those in CM structures. Nonetheless, RC-frame buildings are normally too expensive for most inhabitants in less developed regions.
In this study, as an improvement to the conventional CM buildings for EQ resistance and for the sake of post-EQ restoration, a hybrid masonry – RC (HMR) structure, whose working mechanism is different from that of a conventional CM structure, is proposed. The RC members (i.e. “tie beams” and “tie columns”), which function only as confinement in a CM building, will resist most of gravity load and part of lateral EQ load in an HMR structure, while the wall panels will take most of lateral EQ load and part of gravity load. This is achievable by slightly increasing the sizes and reinforcing ratios of RC members in HMR structures. Such buildings will not collapse in the absence of masonry wall panels because the gravity load bearing system is still intact. On the other hand, as the wall panels in the proposed HMR structure will absorb most of the energy induced by lateral EQ load, severe damages will be controlled within the wall panel region, so that only the wall panels need to be replaced instead of rebuilding the whole structure after the EQ event.
To investigate the mechanical behaviours of masonry assemblages to be used in HMR structures, a series of experimental tests were conducted. Having established the relevant material properties for HMR structures, finite element (FE) simulation was performed to verify its work mechanism.
Prior to applying the FE simulation to HMR structures, the FE technique was first applied to simulate the behaviours of two concrete-brick masonry panels under diagonal compression loading and a CM wall under cyclic lateral loading. The results show a good correlation between the experimental results and the simulated ones. This has validated the feasibility of using the FE software to study the proposed HMR structure.
The theoretical simulation results show that in a properly designed HMR wall, depending on the masonry reinforcing details and the boundary conditions of simulated load cases, about 70% of the gravity load imposed on the RC beam will be transferred to the RC columns and more than 80% of the seismic energy (in terms of strain energy) will be absorbed by the masonry panel. Therefore, it is obvious that the proposed HMR structure is very feasible to replace the conventional CM structure in resisting EQ attacks with no risk of collapse.published_or_final_version
Civil Engineering
Master
Master of Philosophy
14
Al, Mamun Abdullah. "Seismic Damage Assessment of Reinforced Concrete Frame Buildings in Canada". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36188.
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The emphasis on seismic design and assessment of reinforced concrete (RC) frame structure has shifted from force-based to performance-based design and assessment to accommodate strength and ductility for required performance of building. RC frame structure may suffer different levels of damage under seismic-induced ground motions, with potentials for formation of hinges in structural elements, depending on the level of stringency in design. Thus it is required to monitor the seismic behaviour and performance of buildings, which depend on the structural system, year of construction and the level of irregularities in the structural system. It is the objective of the current research project to assess seismic performance of RC frame buildings in Canada, while developing fragility curves as analytical tools for such assessment. This was done through dynamic inelastic analysis by modelling selected building structures and using PERFORM-3D as analysis software, while employing incremental dynamic analysis to generate performance data under incrementally increasing seismic intensity of selected earthquake records. The results lead to probabilistic tools to assess the performance of buildings designed following the National Building Code of Canada in different years of construction with and without irregularities. The research consists of three phases; i) regular buildings designed after 1975, ii) regular buildings designed prior to 1975, and iii) irregular buildings designed prior to 1975. The latter two phases address older buildings prior to the development of modern seismic building codes. All three phases were carried out by selecting and designing buildings in Ottawa, representing the seismic region in eastern Canada, as well as buildings in Vancouver, representing the seismic region in western Canada. Buildings had three heights (2; 5; and 10-stories) to cover a wide range of building periods encountered in practice. The resulting fragility curves indicated that the older buildings showed higher probabilities of exceeding life safety and/or collapse prevention performance levels. Newer buildings showed higher probabilities of exceeding target performance levels in western Canada than those located in the east.
15
GINO, DIEGO. "ADVANCES IN RELIABILITY METHODS FOR REINFORCED CONCRETE STRUCTURES". Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2754713.
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Kuzmanovic, Sasha. "An investigation of the shear design of a reinforced concrete box structure". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq40923.pdf.
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Parsa, Arash. "Finite element modelling of stress concentrations in a reinforced concrete offshore structure". Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292406.
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Xuan, Gang. "Performance Based Design of a 15 Story Reinforced Concrete Coupled Core Wall Structure". Cincinnati, Ohio : University of Cincinnati, 2005. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1133636553.
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Chuang, Tsai-Fu. "Numerical modelling of reinforced concrete structure under monotonic and earthquake-like dynamic loading". Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368434.
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XUAN, GANG. "PERFORMANCE-BASED DESIGN OF A 15-STORY REINFORCED CONCRETE COUPLED CORE WALL STRUCTURE". University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1133636553.
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Magnanini, Nicola. "Seismic retrofit of a reinforced concrete building placed in L'Aquila". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4778/.
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Stokic, Marko. "Numerical modelling of tunnelling-induced damage on reinforced concrete buildings". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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The goal of this study is to gain insight into mechanisms of soil-structure interaction for buildings affected by tunnel excavation and to discuss reliable methods to evaluate the potential damage. Assessing the structural response to excavation-induced deformations involve a combination of both geotechnical and structural aspects, such as soil behaviour, building behavior, soil-structure interaction and modelling techniques.
This study focuses on the behavior of reinforced concrete buildings founded on coarse-grained soils. In particular, reference was made to the case study of new Milan (Italy) metro-line 5, excavated in sandy soils by an earth pressure balance (EPB) machine. Observed volume loss was averagely equal to 0.5%, which did not produce any damage on surrounding buildings due to efficient excavation procedure. The goal of this work is to simulate different scenarios of volume losses and structural configurations through numerical FE simulation. Therefore, a maximum volume loss of 3%, index of inappropriate execution of excavation work was considered. Moreover, the influence of structural stiffness is investigated by taking into account different building configurations including the presence of infills and openings due to doors and windows. A 5-storey RC building founded on a strip footing and interacting with tunnel excavation is modelled in detail. The numerical analyses are performed with the commercial software Abaqus. Damage assessment is carried out both by direct analysis of the stress-strain response of the structure in the numerical analyses and by empirical and analytical methods typically used in the engineering design. Recent researches illustrate that infill masonry walls should be taken into consideration as far as they are most sensitive elements to damage when affected by excavation. This thesis illustrates the beneficial effect, in reducing the deflection ratio and damage to building when modeling it with presence of infills.
23
Prakash, Shruthi. "Nonlinear Finite Element Analysis of Shrinking Reinforced Concrete Slabs-on-ground". Thesis, KTH, Betongbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231361.
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Concrete slabs-on-ground are commonly used in many types of industrial floors, warehouses, highways, parking lots and buildings. Cracks and deflection of slabs are undesired events caused by differential shrinkage, which limits the service life of the slabs. Non-linear behavior of cracks and deflections, interaction of concrete and reinforcement increase the complexity in predicting the occurrence and positioning of cracks. The Eurocode 2 provides a reference for theoretical approximation for design of concrete structures. This thesis intent to investigate the crack behavior of slabs-on-ground subjected to gradient shrinkage using nonlinear finite element analysis, as implemented in the software package Atena 2D. The first part of the thesis is focused on suitable modeling techniques for predicting cracks in concrete slabs-on-ground due to gradient shrinkage. The second part is directed towards parametric studies, performed to explore the significance of varying thickness, length, concrete strength class, bond types, reinforcement content and friction coefficient. The results obtained with the Atena 2D was validated using the design software WIN-statik for calculating the maximum crack width in the context of obtaining realistic results. Finally, the WSP guide recommended parameters were tested as inputs to the model. A slab-on-ground was modeled in Atena 2D considering these as statically indeterminate structures, where both slab and grade were included and the convergence analysis performed under plane stress conditions enabling prediction of the maximum crack widths for increasing applied shrinkage loads. Parametric studies demonstrate the dependency of the slab length, showing that a smaller length reduces the crack width, since such a slab is less constrained by the sub-base. To avoid cracks in the slabs their relative thickness should not be increased above a certain thickness, instead the reinforcement content should be increased. The numerical simulation shows that different concrete strength classes give similar cracks widths. Sand as sub-base provides less crack widths for interface materials EPS, sand and gravel. Although, dry sand as interface material gives similar crack widths as EPS, it is the best to use EPS that is also used to retard the moisture diffusion from the sub-base. The numerical model developed was validated for the recommended values given by the WSP guide, which gives less crack widths and deflections. The numerical model gives less crack widths compared to the Eurocode 2, which considers only the statistically determinant problems overestimating the crack widths. The presented examples demonstrate that the developed model can accurately predict crack formation, crack behavior and vertical deflection in concrete slabs-on-ground subjected to gradient shrinkage loads.
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Kassem, Fidaa. "Reliability of reinforced concrete structures : Case of slabs subjected to impact". Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0096/document.
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Dans le domaine du génie civil, le dimensionnement des structures en béton armé est essentiellement basé sur des démarches déterministes. Cependant, les informations fournies par des analyses déterministes sont insuffisantes pour étudier la variabilité de la réponse de la dalle. Le manque de connaissance des charges appliquées ainsi que les incertitudes liées à la géométrie de la dalle et les caractéristiques des matériaux nécessitent donc l’utilisation d’une approche fiabiliste qui permet la propagation de ces incertitudes dans les analyses déterministes. L'approche fiabiliste est basée sur le principe de couplage mécano-fiabiliste qui consiste à coupler un modèle stochastique et un modèle déterministe. Cependant un couplage mécano-fiabiliste peut être très exigeant en temps de calcul. Dans le cadre de cette thèse, la méthodologie propre aux problématiques des ouvrages du génie civil est développée et validée tout d'abord sur un cas simple de structures en béton armé. Le cas d'une poutre encastrée en béton armée est proposé. Le système est modélisé sous CASTEM par une approche aux éléments finis de type multifibre. Puis la fiabilité d'une dalle en béton armé impactée par une masse rigide à faible vitesse est étudiée en couplant OpenTURNS à Abaqus. Enfin, une enceinte de confinement en béton précontrainte modélisée sous ASTER est étudiée d'un point de vue probabiliste. Seul le problème physique des dalles en béton armé soumises à une chute de colis dans les centrales nucléaires est examiné en détail. Deux modèles déterministes sont utilisés et évalués afin d’étudier les phénomènes dynamiques appliqués aux dalles en béton armé sous impact : un modèle par éléments finis en 3D modélisé sous Abaqus et un modèle simplifié de type masse-ressort amorti à deux degrés de liberté. Afin d’étudier la fiabilité des dalles en béton armé, nous avons couplé les méthodes Monte Carlo et simulation d’importance avec le modèle de type masse-ressort. FORM est utilisée avec le modèle par éléments finis. L’objectif de cette étude est de proposer des solutions pour diminuer le temps de calcul d'une analyse fiabiliste en utilisant deux stratégies dans le cas des dalles impactées. La première stratégie consiste à utiliser des modèles analytiques qui permettent de prédire avec précision la réponse mécanique de la dalle et qui sont moins coûteux en temps de calcul. La deuxième consiste à réduire le nombre d’appels au modèle déterministe, surtout dans le cas des modèles par éléments finis, en utilisant des méthodes probabilistes d'approximation. Ces deux stratégies sont comparées afin de vérifier l’efficacité de chacune pour calculer la probabilité de défaillance. Enfin, une étude paramétrique est réalisée afin d’étudier l’effet des paramètres d’entrées des modèles déterministes sur le calcul de la probabilité de défaillanceReinforced concrete structures (RC) are subjected to several sources of uncertainties that highly affect their response. These uncertainties are related to the structure geometry, material properties and the loads applied. The lack of knowledge on the potential load, as well as the uncertainties related to the features of the structure shows that the design of RC structures could be made in a reliability framework. This latter allows propagating uncertainties in the deterministic analysis. However, in order to compute failure probability according to one or several failure criteria, mechanical and stochastic models have to be coupled which can be very time consuming and in some cases impossible. The platform OpenTURNS is used to perform the reliability analysis of three different structures . OpenTURNS is coupled to CASTEM to study the reliability of a RC multifiber cantilever beam subjected to a concentrated load at the free end, to Abaqus to study the reliability of RC slabs which are subjected to accidental dropped object impact during handling operations within nuclear plant buildings, and to ASTER to study the reliability of a prestressed concrete containment building. Only the physical problem of reinforced concrete impacted by a free flying object is investigated in detail. Two deterministic models are used and evaluated: a 3D finite element model simulated with the commercial code “Abaqus/Explicit” and an analytical mass-spring model. The aim of this study is to address this issue of reliability computational effort. Two strategies are proposed for the application of impacted RC slabs. The first one consists in using deterministic analytical models which predict accurately the response of the slab. In the opposite case, when finite element models are needed, the second strategy consists in reducing the number of simulations needed to assess the failure probability. In order to examine the reliability of RC slabs, Monte Carlo and importance sampling methods are coupled with the mass-spring model, while FORM is used with the finite element model. These two stategies are compared in order to verify their efficiency to calculate the probability of failure. Finally, a parametric study is performed to identify the influence of deterministic model parameters on the calculation of failure probability (dimensions of slabs, impact velocity and mass, boundary conditions, impact point, reinforcement
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Nash, T. "The experimental behaviour of double skinned composite and reinforced concrete shells subjected to external hydrostatic pressure". Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383249.
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Campiz, Ryan. "Coupling Radio Frequency Energy Via the Embedded Rebar Cage in a Reinforced Concrete Structure for the Purpose of Concrete Degradation Sensing". UNF Digital Commons, 2018. https://digitalcommons.unf.edu/etd/836.
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This study focuses on utilizing an energy harvesting system in which a dedicated Radio Frequency (RF) power source transmits RF power via rebar in a reinforced concrete column. The RF power is received and decoupled by a receiver, and is then rectified, boosted, and stored as electrical energy in a supercapacitor, later to be used to make measurements, process data, and communicate to the source via rebar. Two design attempts are presented in this study: (a) one uses single line conduction at 2.4 GHz for RF power transfer; (b) the other uses a more conventional two-line conduction at 8.0 kHz for RF power transfer. Both designs were unsuccessful: (a) the 2.4 GHz attempt demonstrated that no detectable RF power propagated through the concrete medium; (b) the 8.0 kHz attempt demonstrated that too much of the RF power was attenuated through the concrete medium for the energy harvesting circuitry work properly. A potential third design approach is posited in the conclusion of this study. In addition to investigating power transfer designs, a study on the energy harvesting circuitry was performed. A Two-Stage Dickson Multiplier was utilized in conjunction with a Texas Instruments BQ25504 Ultra-Low Power Energy Harvesting Circuit. For these two components to function best, it was shown that the BQ25504’s input filtering capacitor needed to be on the same order of magnitude as the charging capacitors of the Two-Stage Dickson Multiplier, otherwise, if the filtering capacitor was comparatively too large, it would short the output of the Two-Stage Dickson Multiplier. With that said, the lowest power input observed was at 7.83 dBm, but with lower input powers expected to be achievable. Nevertheless, since the second design attempt showed power losses were too significant, it was deemed that at present, unless the power transfer design were improved, then contemporary commercial off the shelf energy harvesting approaches are insufficient.
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OLIVA, VALERIO. "Methodological approaches to the condition assessment of reinforced concrete architectural heritage". Doctoral thesis, Politecnico di Torino, 2022. https://hdl.handle.net/11583/2972790.
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Albostan, Utku. "Implementation Of Coupled Thermal And Structural Analysis Methods For Reinforced Concrete Structures". Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615393/index.pdf.
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Temperature gradient causes volume change (elongation/shortening) in concrete structures. If the movement of the structure is restrained, significant stresses may occur on the structure. These stresses may be so significant that they can cause considerable cracking at structural components of large concrete structures. Thus, during the design of a concrete structure, the actual temperature gradient in the structure should be obtained in order to compute the stress distribution on the structure due to thermal effects. This study focuses on the implementation of a solution procedure for coupled thermal and structural analysis with finite element method for such structures. For this purpose, first transient heat transfer analysis algorithm is implemented to compute the thermal gradient occurring inside the concrete structures. Then, the output of the thermal analysis is combined with the linear static solution algorithm to compute stresses due to temperature gradient. Several, 2D and 3D, finite elements having both structural and thermal analysis capabilities are developed. The performances of each finite element are investigated. As a case study, the top floor of two L-shaped reinforced concrete parking structure and office building are analyzed. Both structures are subjected to heat convection at top face of the slabs as ambient condition. The bottom face of the slab of the parking structure has the same thermal conditions as the top face whereas in the office building the temperature inside the building is fixed to 20 degrees. The differences in the stress distribution of the slabs and the internal forces of the vertical structural members are discussed.
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Miller, Tri Huu. "NONDESTRUCTIVE INSPECTION OF CORROSION AND DELAMINATION AT THE CONCRETE-STEEL REINFORCEMENT INTERFACE". Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194077.
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The proposed study explores the feasibility of detecting and quantifying corrosion and delamination (physical separation) at the interface between reinforcing steel bars and concrete using ultrasonic guided waves. The problem of corrosion of the reinforcing steel in structures has increased significantly in recent years. The emergence of this type of concrete deterioration, which was first observed in marine structures and chemical manufacturing plants, coincided with the increased applications of deicing salts (sodium and calcium chlorides) to roads and bridges during winter months in those states where ice and snow are of major concern. Concrete is strengthened by the inclusion of the reinforcement steel such as deformed or corrugated steel bars. Bonding between the two materials plays a vital role in maximizing performance capacity of the structural members. Durability of the structure is of concern when it is exposed to aggressive environments. Corrosion of reinforcing steel has led to premature deterioration of many concrete members before their design life is attained. It is therefore, important to be able to detect and measure the level of corrosion in reinforcing steel or delamination at the interface. The development and implementation of damage detection strategies, and the continuous health assessment of concrete structures then become a matter of utmost importance. The ultimate goal of this research is to develop a nondestructive testing technique to quantify the amount of corrosion in the reinforcing steel. The guided mechanical wave approach has been explored towards the development of such methodology. The use of an embedded ultrasonic network for monitoring corrosion in real structures is feasible due to its simplicity. The ultrasonic waves, specifically cylindrical guided waves can propagate a long distance along the reinforcing steel bars and are found to be sensitive to the interface conditions between steel bars and concrete. Ultrasonic transducers are used to launch and detect cylindrical guided waves along the steel bar.In this dissertation, in-situ corrosion monitoring technique for reinforced concrete is developed based on two methods - 1) variation of signal strength and 2) the time-of-flight (TOF) variations as the corroded member is loaded transversely. This is the first attempt ever to monitor corrosion inside concrete by measuring the change in the time of flight of guided waves along reinforcing bars as the concrete beam is subjected to bending. Advantages of corrosion monitoring by TOF change are discussed in the dissertation.
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Richardson, Sarah. "In-Situ Testing of a Carbon/Epoxy IsoTruss Reinforced Concrete Foundation Pile". Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1280.pdf.
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Ospina, Larrea Pedro Manuel. "Analysis of an innovative slim floor composite beam conformed by a custom GFRP pultruded profile and reinforced concrete". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/6392/.
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GFRP pultruded profiles have shown to be structural profiles with great stiffness, strenght and very low specific weight, making it a great candidate for the rehabilitation of damaged strucutres. To further enhance the strucutral mechanism of these type of beams, the Slimflor composite structural system has lead as basis for this analysis; by replacing the steel beam with a GFRP pultruded profile. To further increase its composite action, a continuous shear connector has been set as part of the beam cross section as well as its needed reinforcement and fire protection.
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Rajman, Martin. "Železobetonová skeletová konstrukce nákupního centra". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225356.
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The point of my diploma thesis was design elements of reinforced concrete frame structures mounted single – storey mall.I choose the most exposed to the specified longitudinal frame structure, where I assumed the most highly stressed elements, which I subsequently designed. All documents and calculations are illustrated in part B2 of my diploma thesis.
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Rendon, Adam Russell. "DETERMINATION OF THE MODAL PARAMETERS OF A FIVE STORY REINFORCED CONCRETE STRUCTURE USING ULTRA-LOW LEVEL EXCITATION AND COMPUTATIONAL ANALYSIS". DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/687.
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The determination of a building’s modal parameters (natural periods and mode shapes) using ultra-low level forced vibration testing and analytical modeling were critically compared. The structure utilized for this experiment is the Robert E. Kennedy Library on the campus of California Polytechnic State University San Luis Obispo, a five-story reinforced concrete shear wall structure. The specific testing procedure used has been verified to produce accurate results in smaller buildings, but the Kennedy Library represents the most massive subject structure. Other characteristics of this structure that make it unique include a large atrium at the center of the building and modes that are closely spaced in the frequency domain. Comparing the results from the computational models and the experimental analysis showed that the computational models underestimated the building periods by approximately 6-12%. This discrepancy in the results was attributed to an underestimation of the building mass, possible soil-structure interaction, and likely cracking of the concrete slab and shear walls. Modeling of the shear walls as both line elements and area elements was also explored and the consequences of each were determined.
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Vitálišová, Barbora. "Návrh a posouzení vybraných částí ŽB nosné konstrukce". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392081.
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The diploma thesis deals with the design of selected parts of reinforced concrete elements of the exhibition room. Simultaneously, the optimization of selected elements according to valid standards and Eurocodes was carried out and the impact of these changes on the economy of construction was developed.
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Eliášová, Kristýna. "Železobetonová nosná konstrukce". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227461.
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My diploma thesis presents structural design of an apartment block in Praha Smíchov. It is a reinforced concrete column structure with six floors. Plane dimensions of the building are 19x36 m. The project includes design of main structural system elements - columns, ceiling plate, foundation and staircase structure.
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Konečný, Michal. "Alternativní řešení montovaného železobetonového skeletu výrobní haly". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-391882.
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The aim of the thesis is to design a load-bearing precast concrete structure of production facility. Part of the diploma thesis is to design alternative roofing construction including economic comparison. Internal forces analysis was processed by Dlubal RFEM 5.16 software. In order to find out the expected results, were created simple bar models and the spatial model of the structure was processed later. Structural design report was created for selected elements of the concrete structure including drawings.
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Elshesheny, Ahmed. "Dynamic soil-structure interaction of reinforced concrete buried structures under the effect of dynamic loads using soil reinforcement new technologies. Soil-structure interaction of buried rigid and flexible pipes under geogrid-reinforced soil subjected to cyclic loads". Thesis, University of Bradford, 2019. http://hdl.handle.net/10454/18312.
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Recent developments in constructions have heightened the need for protecting existing buried infrastructure. New roads and buildings may be constructed over already existing buried infrastructures e.g. buried utility pipes, leading to excessive loads threatening their stability and longevity. Additionally applied loads over water mains led to catastrophic damage, which result in severe damage to the infrastructure surrounding these mains. Therefore, providing protection to these existing buried infrastructure against increased loads due to new constructions is important and necessary.
In this research, a solution was proposed and assessed, where the protection concept would be achieved through the inclusion process of geogrid-reinforcing layers in the soil cover above the buried infrastructure. The controlling parameters for the inclusion of geogrid-reinforcing layers was assessed experimentally and numerically. Twenty-three laboratory tests were conducted on buried flexible and rigid pipes under unreinforced and geogrid-reinforced sand beds. All the investigated systems were subjected to incrementally increasing cyclic loading, where the contribution of varying the burial depth of the pipe and the number of the geogrid-reinforcing layers on the overall behaviour of the systems was investigated. To further investigate the contribution of the controlling parameters in the pipe-soil systems performance, thirty-five numerical models were performed using Abaqus software. The contribution of increasing the amplitude of the applied cyclic loading, the number of the geogrid-reinforcing layers, the burial depth of the pipe and the unit-weight of the backfill soil was investigated numerically.
The inclusion of the geogrid-reinforcing layers in the investigated pipe-soil systems had a significant influence on decreasing the transferred pressure to the crown of the pipe, generated strains along its crown, invert and spring-line, and its deformation, where reinforcing-layers sustained tensile strains. Concerning rigid pipes, the inclusion of the reinforcing-layers controlled the rebound that occurred in their invert deformation. With respect to the numerical investigation, increasing the number of the reinforcing-layers, the burial depth of the pipe and the unit-weight of the backfill soil had positive effect in decreasing the generated deformations, stresses and strains in the system, until reaching an optimum value for each parameter. Increasing the amplitude of the applied loading profile resulted in remarkable increase in the deformations, stresses and strains generated in the system. Moreover, the location of the maximum tensile strain generated in the soil was varied, as well as the reinforcing-layer, which suffered the maximum tensile strain.Government of Egypt
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Švehla, Ľuboš. "Vysokoškolský internát". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226334.
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New university dormitory in Trnava with five stories is based on the flat land. The first floor is the technical part of the building, space for a temporary accommodation and a separate sales area. Part of the second floor consists of offices for administration, the second part of the floor, as well as the other three stories are designed as a unit system for student accommodation. Total bed capacity is designed for 134 students. The bearing structure of the building is reinforced concrete monolithic skeleton with infill perimeter walls of ceramic bricks. The flat roof of the building is not walkable.
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Ceccon, Jorge Luiz. "Análise dos efeitos de segunda ordem em pilares solicitados a flexão oblíqua composta". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3144/tde-07112008-105053/.
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Na verificação do estado limite último das estruturas reticuladas em concreto armado se tem sempre os pilares solicitados à flexão oblíqua composta, seja devido a momentos fletores transmitidos pelas vigas ou lajes ou devido a imperfeições construtivas ou por ações normais ao eixo da peça comprimida, atuantes entre seus pontos de vinculação. Neste trabalho se está comparando os resultados que se obtém por dois processos de cálculo, quais sejam, a) Integração numérica com desacoplamentos das flexões nas duas direções principais de inércia com o uso da rigidez secante obtida de diagrama momento-curvatura, ou seja, os esforços de segunda ordem são calculados em cada direção como se não houvesse a solicitação de flexão na direção ortogonal e ao final se verifica a segurança da peça no Estado Limite Último considerando a flexão oblíqua composta; b) integração numérica considerando a flexão oblíqua composta com a curvatura obtida de diagrama momento-curvatura ponto a ponto já no cálculo dos efeitos de segunda ordem. Foram processados 215.740 pilares cuja análise conduz à conclusão de que se pode usar o procedimento citado no item (a) acima, com segurança e sem prejuízo da economia.At check reticulated reinforced concrete structures in the ultimate limit state one always have the columns requested by a compression with biaxial bending , be due bending moments transmitted bay beams or slabs or due constructions imperfections or actions normal to the axis of the compressed piece acting between its points of attachment. This work is to compare the results that are obtained by two methods of calculation, which are: a) Numerical integration in each main direction of inertia with the use of secant stiffness obtained from bending-curvature diagram, it is, the second order efforts are calculated in each direction as if there was not request bending in the orthogonal direction and the end check the safety at ultimate limit state of the column by considering the biaxial bending; b) Numerical integration in each main direction of inertia with curvatures obtained point to point of moment-curvature diagrams, that consider the biaxial bending, to calculate the second order effects. Were processed 215.740 columns whose analysis leads to the conclusion that we can use the procedure mentioned in tem a) above, safely and without prejudice to the economy.
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Bolander, Julie Christine. "Investigation of Torsional Effects on Thirteen-Story Reinforced Concrete Frame-Wall Structure Modeled in ETABS and SAP2000 Using Linear and Nonlinear Static and Dynamic Analyses". Thesis, University of California, San Diego, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1557303.
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The primary objective of this thesis is to evaluate the effects of torsion on the nonlinear seismic response of a thirteen-story reinforced concrete frame-wall structure with an asymmetric stiffness in plan. The NEHRP building structure, located in Berkeley, CA and previously designed by André Barbosa, was modeled in ETABS and SAP2000 to perform several analyses. The models accounted for realistic cracked concrete section stiffnesses, expected material properties, and nonlinear plastic hinges. Due to limitations of ETABS in performing nonlinear dynamic time history analysis, the model was exported to SAP2000. An asymmetric lateral stiffness model was created by moving one of the shear walls from the center of the building toward the outside of the building. OpenSees was used to find the nonlinear hinge moment-rotation relationships.
Using a suite of seven ground motion record pairs, an essentially linear dynamic time history analysis was performed on the symmetric and asymmetric ETABS models. The SAP2000 models were used to perform a series of nonlinear static (pushover) analyses. Fully nonlinear, including material and geometric nonlinearity, time history analyses were performed on the SAP2000 models using the seven ground motion pairs, appropriately cut to shorter lengths to reduce the analysis run-time. In each analysis case, the results of the symmetric and asymmetric models were compared. Overall, the asymmetric model typically experienced torsional effects and larger displacement responses than the symmetric model. The more nonlinear the structure behaved, the more influence torsion had on the response of the model with asymmetrically-placed shear walls.
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PATIL, GOPAL. "SEISMIC BEHAVIOUR OF THE IRREGULAR RC STRUCTURE SUBJECTED TO SINGLE AND MULTIPLE EARTHQUAKE EXCITATIONS". Thesis, 2023. http://dspace.dtu.ac.in:8080/jspui/handle/repository/19975.
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Urban infrastructure often comprises buildings with irregular designs, influenced by
occupational and architectural requirements. Irregularities can be observed in various
aspects of a building, such as its floor plan, elevation, distribution of vertical elements,
and allocation of mass across different levels. Finding perfectly regular buildings in
reality is rare, making them more theoretical than practical. However, these irregularities
can pose a significant risk during seismic activity, as they can amplify displacement and
concentrate stresses within the structural components, potentially leading to severe
damage and even collapse. One type of irregularity is vertical irregularity, which refers
to variations in mass, stiffness, strength, or geometry along the height of a building.
Another kind is rotational or in-plan irregularity, that develops whenever the centre of
masses and rigidity are not aligned along a similar vertical direction at each floor level.
When lateral forces or earthquakes occur, the resistive force operates along the centre of
stiffness, whereas the force of inertia acts along the centre of mass. The operation of the
structure is torsional if it possesses in-plan eccentricity.
This research aims to investigate the effects of repeated seismic waves on irregular RC
buildings commonly found in urban infrastructure. Specifically, he main objective of the
study is to assess the effects of mass and stiffness anomalies along the height of the
building along with torsional irregularities in the structure's plans. To analyse these
effects, nonlinear time history analysis is conducted using the software ETABS 20,
comparing torsional responses under various scenarios. The analysis reveals that
irregularities arising from differing shear wall positions exhibit more pronounced
torsional irregularities compared to mass and stiffness irregularities, especially when
subjected to single strong earthquakes or repeated earthquakes. The results demonstrate
that double event earthquakes result in greater torsional irregularity compared to single
events and triple events, while a triple event of moderate earthquakes yields similar results
to a single event of a strong earthquake. This study provides valuable insights into the
torsional behaviour of irregular reinforced concrete buildings when exposed to repeated
earthquakes. Overall, the results highlight the critical importance of shear wall
placements to assessing the torsional behaviour of such buildings, emphasising the need
to take them into account when designing earthquake-resistant structures. The evaluation
of different techniques involves comparing methods such as column resizing and
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reorientation, implementing Lead rubber base isolation systems to isolate a building's
foundation from vibrations and seismic activity, and incorporating friction viscous
dampers to minimize torsional impact during single and repeated earthquake excitations
in the most vulnerable scenarios. The results clearly demonstrate the high effectiveness
of these techniques in reducing torsional irregularity in structures. Notably, the
incorporation of friction viscous dampers proves to be the most advantageous, resulting
in the lowest displacement and minimal torsional irregularity compared to the other two
techniques.
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Wu, Yu-Hua, i 巫雨驊. "Investigation on the Seismic Capacity of Plane Irregular Reinforced Concrete Building Structures". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/03207917116229030653.
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碩士淡江大學
土木工程學系碩士班
101
The disasters of previous earthquakes showed that most of the severe damages from the structures were happened to flat or irregular facade ones when the earthquake hit. The main cause was such structures often occur in seismic torsional deformation and stress concentration. However, it is unavoidable that the plane irregularities keep appearing in the structures of buildings under the rising economy. Furthermore, as Taiwan is located on the Pacific seismic zone, the capacity of flat irregular building structures when the earthquake strikes becomes a topic which is worthy of study. For the irregular plane reinforced concrete structures in this thesis, it takes the concave corners and quality two kinds of sixth floor building structure as an example. First, it conducts with the structural analysis and design, and then proceeds with pushover analysis for seismic capacity evaluation. At the same time, analyzing both the irregular seismic capacity and the impact, which are compared to different eccentricity and vertical force, different dimension of the beam cross-section and different cross-sectional dimensions of the planar column. In conclusion, the above process are in order to comprehend the influences for structural seismic capacity of different effect factors, as well as the general seismic capacity evaluation mode of assessing the applicability in such structural seismic capacity. According to the result of the study, different eccentricity and vertical force distribution on different structural seismic capacity analysis results leads to different degrees of impact. Hence, the seismic capacity analysis should be discreetly chosen. In addition, the extension of beam and column section may increase the seismic capacity of building structure. Nevertheless, the extension of the beam cross-section dimensions of toughness may decrease the capacity of building structures while the extension of the column section consolidated the toughness capacity of building structure. The results of this study are available for engineering practitioners and the academia as a reference.
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Jiang, Yin-Xian, i 江育賢. "A Study for Concrete Structure Reinforced". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/98604974423276051626.
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碩士國立臺灣科技大學
營建工程系
90
ABSTRACT The object of this study is to develop a new way to construct reinforced concrete structures. The main difference is the construction procedure is changed to build the steel reinforcement first. There are two kinds of steel frame were suggested. The first one uses steel sheets to build the steel frame. The second one uses traditional reinforcement plus steel sheets to build the steel frame. However, these steel frames are different from the steel sections used in the steel reinforced concrete structures. The beam unit, column unit, and connection unit were developed in this study. All these units were designed for easy construction and improved structural strength. Also, all the faults could be made in the traditional reinforcement construction can be avoided. Therefore the most important improvement could be obtained through this new suggestion is a better quality. The suggested steel frame should be treated as a three-dimension structure. This frame can resist forces come from any direction instead of the longitudinal strength only. Due to the strong connection between frame members, the ductility of the reinforced concrete member can be improved a lot also. An economic study was made to compare the cost of traditional reinforced concrete structures and the suggested new structure. It was found that the construction cost can be increased a little around 10%. However, the construction time can be reduced in a range of 30% to 50%. Many new technologies like high-strength concrete, composite plate, light-weight partition wall, etc. can be integrated to this new method to get a light weight but high-strength concrete structure, which is suitable for the high-rise buildings.
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TSAI, TE YUAN, i 蔡德源. "Object-orirnted reinforced concrete structure design". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/02091753290706872375.
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Lin, Wen-Long, i 林文隆. "Seismic Vulnerability Analysis of Reinforced Concrete Structure". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/41551051767766485463.
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碩士國立中央大學
土木工程研究所
95
Sensible earthquakes hit Taiwan frequently. An earthquake has catastrophic characteristics of low frequency and devastating disaster. In this case, in the earthquake loss, structure damage assessment plays an important role. Also, this provides reasonable and reliable results of structure earthquake damage assessment to be as applications of earthquake catastrophe risk management. In the earthquake damage assessment, this article applies nonlinear dynamic analysis structure model to stimulate the structure possible damage condition. The main cause of forming earthquake damage is that dynamic response exceeds in structure itself damaging threshold. Therefore, story drift ratio is adopted to determine damage state of building. damage state could be identified with different drift ratio. This will help to assess buildings damage rapidly according to establish fragility curve of building. The seismic structure damage appraisal is to establish all kinds of structure fragility curve, this article aim to do researches on typical reinforced concrete via theoretical analysis method and determine typical structure vulnerability analysis parameters in Kaohsiung County areas. This will help to assess similar buildings under earthquake which causes different damage state and probability as well as to evaluate the economic benefit of building retrofitting or reference of earthquake risk management in the future.
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Lee, Bo-Yan, i 李柏彥. "Limit Load Analysis of Steel Reinforced Concrete Structure". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/246scb.
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碩士朝陽科技大學
營建工程系碩士班
94
First, this study refers the national code of the Republic of China, textbook and domestic experiment about steel structure reinforced concrete (SRC). The SRC component of experimentation was transformed to the equivalent steel component. The equivalent steel component was input to SAP2000 structure analyzing program. Then, this project confer the relationship of the initial stiffness and limit load of equivalent steel component analyzed by SAP2000 and tested by experiment. The transferred equivalent cross-section theory was applied to New Engineering Building at Chaoyang University of Technology. The pushover analyzing method of SAP2000 was used to study the failure mode and the earthquake bearing ability. In order to know the contribution of SRC structure, the original steel columns was replaced by SRC columns in the second floor and the third floor. Finally, this study compares the minimum earthquake force according to the code and the 921 earthquake force. Earthquake thrust in 921 earthquake and the base force analyzed by SAP2000 were used to realize that whether New Engineering Building can resist the similar earthquake attack or not.
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Chen, Zhi-Hong, i 陳志宏. "Research of Damage Index of Reinforced Concrete Structure". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25734364164134865364.
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碩士國立臺灣大學
土木工程學研究所
98
This thesis is for the purpose of discussing the damage index of buildings under the earthquake over the years of definition by scholars, the so-called damage index,is refers to the structure to receive a succession of structure response parameter which under the earthquake function, and to establish a set of computation flow the damaged condition size. We may because of the damage index, to cognitive structure of extent of damage preliminary to judge this structure whether suits the housing or use again. We use the structure to suffer a strong earthquake to make the system enter the non-linearity, cause the natural frequency of structure to start to change and judges its damage. This thesis simulates behavior of the nonlinear system in use Least-Squares Method to get the equivalent linear damping and frequency, and confirms its accuracy by Newmark-β Method, after judges the extent of damage of structure by the Maximum softening damage index, and improves it by the frequency with stiffness relations to damage index to promote its sensitivity. Then uses Park and Ang damage index this index is formed by the structure displacement and the energy dissipation under the carrying capacity, and considered its structural material parameter, the Maximum softening damage index, stiffness destruction index and Park and the Ang destruction index will do reorganizes and compares its good and bad points. Finally, we can get the time history and material parameter of frames of one layer three cross frame collapse tests in National Center for Research on Earthquake Engineering to treat as measured value, carries on the example analysis. By way of identification as well as calculates result of each destruction index to make a comparison.
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Deng, Fu-Sheng, i 鄧福勝. "Numerical Simulations of Reinforced Concrete Structure Containing Brick Wall". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/81331179546250485600.
Pełny tekst źródłaStreszczenie:
碩士國立中央大學
土木工程研究所
89
The behaviors of reinforced concrete structures containing brick wall under earthquake loading are quite complicated. It is very difficult to analyze the problem analytically. Experiment and numerical simulation are two possible solutions to extract reference information for the development of design code. However, the experimental approach requires much effort and expense to built very limited number of specimens to explore the behaviors of RC structures. The main advantage of using numerical simulation code to study the structural problem is that any detail response of the system can be detected easily from the calculated data. In this thesis, a computation code is developed based on the finite element method (FEM) and the discontinuous deformation analysis (DDA) theory. Each brick is modeled as a DDA block patched with finite element mesh. After cracking of mortar, the multi-body dynamics and contact analysis among bricks and RC frame are dealt by the DDA theory. Truss element is used to model the behavior of reinforcement inside the concrete and is tied up with the concrete at the node of concrete element. Both the nonlinear behaviors of the reinforcement and concrete material are considered into the analysis. To model the behavior of the mortar between bricks, a special interface element is developed. This element can provide suitable bond force between two blocks due to mortar. This interaction force can be reduced according to the interfacial friction and contact laws if interfacial cracking is identified. Besides, smear damage model of cracked concrete material is also acquired to adjust its coefficients of elasticity at Gaussian points according to the direction of crack surface. The accuracy and effectiveness of this simulation code were verified by some benchmark problems and experiment results of large-scale structural tests.
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Chang, Chung-chuan, i 張崇川. "The improvement of Concrete Structure Reinforced by Steel Frame". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/88587706270066896169.
Pełny tekst źródłaStreszczenie:
碩士國立臺灣科技大學
營建工程系
98
The improvement of Concrete Structure Reinforced by Steel Frame ABSTRACT This study is based on the improvement of Concrete Structure reinforced by Steel Frame. The object is to combine steel frames’ tensile and concrete’s compressive strengths to resist external loads. The wrapped plate steel and the inside reinforcement can be connected into an integrated frame structure to the largest advantages in mechanic. Also, it’s an efficient way to control cost because low labor demand、easy inspection and improved construct on quality. The self tapping screws 、bolt and welding to facility easier and faster unit combination. According to the improvement of concrete structure reinforced by steel frame, its beams and columns are established by units. The object is wrapped steel plate can also play the roles of tensile reinforcement and shear stirrups to increase the member’s strength . Special steel plate with grid increase the bond strength to concrete. Also, by designing steel ring to connect steel plate and interior reinforcement, we can improve the performance of whole structure. If this new method can combine with high-performance concrete, it will reduce sectional size and weight of building. As a result, it’s will be beneficial for tall building and earthquake design. 關鍵字 1.鋼構架混凝土工法：Concrete Structure Reinforced by Steel Frame 2.自攻螺絲：self tapping screws 3.格子樑：grid 4.鋼環：steel ring 5.高性能混凝土：high-strength concrete structure
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He, Ming-En, i 何明恩. "Vibration Response of Reinforced Concrete Structure Under Moving Load". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/05141472914887998168.
Pełny tekst źródłaStreszczenie:
碩士國立臺灣海洋大學
系統工程暨造船學系
94
Abstract This paper aims at the discussion of the vibration analysis model of RC Structure subjected to moving load by using the finite- element method situation of such RC Structure subjected to measurement to moving load are mainly the vibration generated by the train passing-by the viaduct of a MRT system or by the bus running on the floor of a joint-construction building acting an a traffic transfer terminal. In the finite- element analysis (FEA) of the joint-construction RC building , shell 63 element and beam4 element are used ; while in the FEM of the RC viaduct , The solid 45 element are used for the mach generation of pier-beam and bridge floor . Both the exciting force generated by the moving trains or bused and input to the RC Structure are calculated form the measurement or analysis mobility functions and the in situ vibration measurement . the comparisons of the vibration result form FEM of both RC joint-construction building and viaduct with in that of measurement show that the error range in within dB. Meanwhile , the predicted vibrations in the RC building sued for a traffic transfer station have checked whether they comply with the Gordon environmental vibration standard or not in the paper . Also four kinds modeling for different boundary condition are carried out in the FEA of RC viaduct . In whir the 5-span model with both ends of bridge floor of free boundary condition wire result in good approximation to that by measurement . besides the vibration response spectrum in the range of 31.5-2000 Hz during the passing-by trains at reversal points of the bridge floor have beam discussed and characterized.