Dissertations / Theses on the topic 'Concrete frame buildings'
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1
Yuan, Mengfei. "LATERAL DISPLACEMENT OF REINFORCED CONCRETE FRAME BUILDINGS." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417621416.
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Grönvall, Stina, Matilda Lundquist, and Bergli Clara Pedersen. "Embodied carbon for residential buildings : A life cycle assessment for concrete and wooden framed buildings." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-225557.
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The consulting firm Atkins has developed a tool to help constructers plan urban areas but the tool is lacking data about embodied carbon in Sweden. The embodied carbon is the total carbon dioxide equivalents that are emitted from the material used in constructing a residential building as well as the energy used at the construction site and during demolition. In this thesis, the embodied carbon for a concrete framed building and a wooden framed building is calculated and presented. The mapping of embodied carbon for the two different framed buildings is done with a life cycle assessment perspective. In order to structure the studied system, the life cycle of the buildings is divided into three stages. The first stage includes data and calculations about the extraction and manufacturing of the most common building materials as well as the transportation to construction site. Stage 2 presents information about theon-site construction which includes, among other things, use of machines for constructing a residential building. In the third stage, data regarding demolition and end of life management are presented and calculated. All these three stages are added and a value for total embodied carbon for concrete framed residential buildings and wooden framed ones is presented in the result. The final result shows that the studied concrete framed residential building contains more embodied carbon than the wooden framed one. Further, stage 1 represents the largest part of embodied carbon, 87% for the concrete frame and 84% for the wooden frame, and stage 2 represents a very small part for both types of buildings, 1% for the concrete frame and 2% for the wooden fame.
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Han, Mengyu. "Application of Base Isolation Systems to Reinforced Concrete Frame Buildings." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35722.
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Seismic isolation systems are widely used to protect reinforced concrete (RC) structures against the effects of strong ground motions. After a magnitude 6.6 earthquake, the outpatient building of Lushan People’s hospital in China remained in good condition due to the seismic isolation technology, while the non-isolated older outpatient building nearby experienced major damage. The building provides a good opportunity to study and assess the contribution of isolation systems to seismic performance of RC structures. In the current research project, the isolated outpatient building was modelled and analyzed using computer software SAP2000. The post-yield behaviour of the structure was modelled by assigning multi-linear plastic links to frame objects. The rubber isolators were represented by rubber isolator link elements, assigned as a single joint element between the ground and the superstructure. The isolated structure was subjected to four earthquake records with increasing intensity. The performances of the isolated structure were compared with those of the fixed-base structures in terms of lateral inter-storey drifts, peak absolute floor accelerations, and residual drifts. The laminated rubber bearings, the high damping isolation devices, composed of rubber bearings and viscous dampers, and the hybrid isolation system of rubber bearings and friction pendulum bearings were analysed. The effectiveness of the three base isolation systems considered in enhancing structural performance was investigated. The results show the level of improvement attained in seismic response by each system. They also illustrate that the rubber bearings coupled with friction pendulum bearings produce the best drift control without causing excessive horizontal displacements at the base level and without adversely affecting floor accelerations.
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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.
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Lidholm, Maria, Camilla Odelbrink, and Josefin Sandwall. "Exergy Analysis of two Residential Buildings with Wooden and Concrete Frame." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-179496.
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Jiang, Yimin. "Torsional response of reinforced concrete frame buildings subjected to blast loading." Thesis, University of Ottawa (Canada), 2008. http://hdl.handle.net/10393/27990.
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This study is intended to contribute to the understanding of the torsional behaviour of buildings subjected to blast loading. The scope of the investigation involves a 10-storey symmetrical reinforced concrete frame structure designed in accordance with CSA Standard A23.3 (2004), and the provisions of the National Building Code of Canada (2005). The building was analyzed under different magnitudes of explosions, triggered at different distances and location such that the building would be subjected to lateral impulsive forces causing torsion. Elastic dynamic time-history analyses were conducted using software ETABS under impulsive forcing functions caused by the detonations of 100 kg, 200 kg, 300 kg, 500 kg, and 1000 kg TNT at distances of 5 m, 10 m, and 20 m from the building, at three different eccentricities within the plane of building floor to create torsional eccentricities relative to the centre of rigidity. The performance of structure was evaluated by considering interstorey drift, floor rotations, lateral displacements, and P-M capacity/demand ratios for columns.
The results indicate that the perimeter columns, especially the corner columns are affected most when the building is subjected to blast loadings. The torsional building response increases with the amount of TNT. It is related to the location of the explosion relative to the building, and increases with torsional eccentricity. On the other hand, the torsional response decreases with distance from explosion to building. Maximum interstorey drifts are closely related to the eccentricity of blast loads. This effect can be neglected in practical applications for small size charges and distant explosions. For example, an explosion caused by less than 500 kg TNT at distances of 20 m and longer would produce very small interstorey drifts and the effects of the eccentricity of blast loads could be neglected in such buildings.
7
Haselton, Curt B. Deierlein Gregory G. "Assessing seismic collapse safety of modern reinforced concrete moment-frame buildings." Berkeley, Calif. : Pacific Earthquake Engineering Research Center, 2008. http://nisee.berkeley.edu/elibrary/Text/200803261.
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Bechtoula, Hakim. "Seismic performance of moderate or low rise reinforced concrete frame buildings." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144873.
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Biddah, Ashraf Mahmoud Samy. "Seismic behaviour of existing and rehabilitated reinforced concrete frame connections." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ30074.pdf.
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Huang, Kai. "Continuum MDOF model for seismic analysis of wall-frame structures /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20HUANG.
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Peng, Brian Hsuan-Hsien. "Seismic performance assessment of reinforced concrete buildings with precast concrete floor systems." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2009. http://hdl.handle.net/10092/3103.
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In the seismic design of reinforced concrete frames, plastic hinges are allocated to beams such that a ductile beam-sway mechanism will form in preference to other less ductile mechanisms in the event of a major earthquake. This is achieved by ensuring that the flexural strength of columns is greater than that corresponding to the maximum likely flexural strength of beam plastic hinges.
Recent experimental studies in New Zealand have shown that elongation of ductile beam plastic hinges, and its interaction with nearby floor slab containing precast-prestressed floor units, increases the strength of beams much more than that specified in New Zealand and American Concrete standards. This level of strength enhancement has raised concern on the adequacy of the current design provisions. To further investigate this problem, a research project was initiated to examine the strength of beam plastic hinges in reinforced concrete frames containing precast-prestressed floor units.
In this research, the strength of beam plastic hinges was assessed through experimental and analytical studies. A three-dimensional, one-storey, two-bay reinforced concrete moment resisting frame with prestressed floor units and cast-in-situ concrete topping was tested under quasi-static displacement-controlled cyclic loading. The experimental results provided insight into the mechanics associated with frame-floor interaction. Subsequently, improved design specifications were proposed based on the observed behaviour.
To analytically predict the beam-floor interaction, a ductile reinforced concrete plastic hinge multi-spring element was developed and validated with experimental results from cantilever beam and frame sub-assembly tests reported in the literature. The comparisons have demonstrated the ability of the proposed plastic hinge element to predict the flexural, shear, axial, and most importantly, elongation response of ductile plastic hinges.
The proposed plastic hinge element was implemented into an analytical model to simulate the behaviour of the frame-floor sub-assembly tested in this research. Specially arranged truss-like elements were used to model the linking slab (the region connecting the main beam to the first prestressed floor unit), where significant inelastic behaviour was expected to occur. The analytical model was found to be capable of predicting the non-linear hysteretic response and the main deformation mechanisms in the frame-floor sub-assembly test.
The analytical frame-floor model developed in this study was used to examine the effect of different structural arrangements on the cyclic behaviour of frames containing prestressed floor units. These analyses indicated that slab reinforcement content, the number of bays in a frame and the position of frame in a building (i.e., perimeter or internal frame) can have a significant influence on the strength and elongation response of plastic hinges.
12
Idrus, Arazi Bin. "Development of a procedure and tool for evaluating and selecting concrete floor systems for concrete frame buildings." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395935.
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Amiri-Hormozaki, Kambiz. "Effects of scaling of earthquake excitations on dynamic response of reinforced concrete frame buildings." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26564.
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The objective of this study was to evaluate the effects of various scaling techniques of real accelerograms on the response of medium height moment-resisting reinforced concrete frame buildings. Detailed inelastic time-history analyses were conducted on three reinforced concrete frame buildings.
Three scaling methods were used, i.e. (i) based on the spectral ordinate at the fundamental period of the building, (ii) based on the area under the spectral curve between the first and the second natural periods of vibration of the building (referred to as partial area), and (iii) based on the total area under the spectral curve throughout the whole period range (referred to as full area). Each scaling was conducted relative to the corresponding design spectrum (for Vancouver or Montreal) as prescribed in the 2005 edition of the National Building Code of Canada (NBCC 2005).
The response parameters that were investigated in this evaluation study were the interstorey drifts, curvature ductility demands in the beams, and curvature ductility demands in the columns of the buildings. (Abstract shortened by UMI.)
14
TUNC, GOKHAN. "RC/COMPOSITE WALL-STEEL FRAME HYBRID BUILDINGS WITH CONNECTIONS AND SYSTEM BEHAVIOR." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1020441384.
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Galin, Sanja. "Selection and Scaling of Seismic Excitations for Time-History Analysis of Reinforced Concrete Frame Buildings." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20657.
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Time history-analyses of building structures have been used for a quite long time for research at universities. Considering the advantage of time-history analysis relative to the equivalent static force method, the National Building of Canada and other modern building codes around the world require the use of time-history analysis in the design of specified types of buildings located in seismic regions. One of the main issues in the use of time-history analysis is related to the selection and scaling of the seismic excitations (i.e., accelerograms) to be compatible with the design spectrum for the location considered. Currently, both recorded (i.e., “real”) accelerograms and artificial accelerograms are used in the analyses.
The objective of this study is to determine the effects of the selection and scaling of seismic excitations on the response of reinforced concrete frame buildings. Three reinforced concrete frame buildings with heights of 4 storey, 10 storey and 16 storey, designed for Vancouver (high seismic zone) were used in this study. Five sets of seismic excitations were used in the analysis – one set of “real” accelerograms, and four sets of artificial accelerograms obtained by different methods. All sets were scaled to be compatible with the design spectrum for Vancouver. Both linear and nonlinear time history analyses were conducted on the buildings considered. Interstorey drifts and storey shear forces were used as response parameters.
The results from the linear analysis show that both the interstorey drifts and the shear forces are affected significantly by the type of the excitation set. Similarly, the effects of the type of the seismic excitations on the drifts from nonlinear analysis are substantial. On the other hand, the influence of the excitation sets on the storey shears from nonlinear analysis are quite small.
Based on the results from this study, sets of scaled real records are preferred for use in time-history analysis of building structures. If such records are not available, then sets of simulated accelerograms based on the regional seismic characteristics should be used.
16
Ogawa, Sachio. "A simplified procedure for assessing failure probabilities of reinforced concrete frame buildings under earthquake loading." Thesis, University of Canterbury. Civil Engineering, 1988. http://hdl.handle.net/10092/5864.
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The thesis argues the need for a more rational structural code, and as a major step in its attainment describes the development of a simplified technique for assessing the probability of failure of structures due to earthquake effects.
Previous approaches to the development of a rational code are discussed critically and their limitations are described. A major problem is shown to be the difficulty of assessing failure probabilities for complete structures, even using the simplified First-Order Second-Moment approach. The difficulty is illustrated by applying the First-Order Second-Mount method to a simple portal frame structure.
A consistent approach to the analysis of seismic failure probabilities of complete structures is then developed. Cumulative plastic strain energy is used as an overall damage measure, with an interstorey drift limit as a failure criterion. The relationship of the two is established using three separate analyses for estimating:
1. the total cumulative plastic strain energy absorbed by an entire structure;
2. the proportion of total energy absorbed by each storey; and
3. the maximum interstorey drift induced by the energy in each storey.
Finally, a First-Order Second-Moment approach is used for obtaining probabilities of failure. The technique is developed in detail only for reinforced concrete frame structures, though the approach is more universally applicable.
The analysis is relatively complex, but it nevertheless involves a number of simplifying assumptions. These are discussed, and are also the subject of sensitivity analyses.
The analysis is applied to various trial structures. It is tentatively concluded that the seismic reliability implied by New Zealand codes is a little low, compared with results obtained elsewhere.
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Thinley, Kinzang. "Assessment of seismic performance of reinforced concrete frame buildings with or without infill wall in Bhutan." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/52943.
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This study is the first comprehensive research work undertaken on the seismic performance of the masonry infilled reinforced concrete frame buildings in Bhutan. An extensive numerical investigation is carried out and probabilistically predicted the damages of the existing buildings in Bhutan under the expected earthquake ground motions. The findings from this study would go a long way in saving the lives of the people and their properties from the earthquakes in the future.
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Shiu, Kwai-king Joe. "A critical evaluation of concrete and steel frame buildings in Hong Kong with regard to waste minimization /." View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34739373.
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Shiu, Kwai-king Joe, and 蕭桂瓊. "A critical evaluation of concrete and steel frame buildings in Hong Kong with regard to waste minimization." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B45013226.
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Dahlin, Tobias, and Magnus Yngvesson. "Construction Methodology of Tubed Mega Frame Structures in High Rise Buildings." Thesis, KTH, Betongbyggnad, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147328.
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As a response to the ever denser cities, skyscrapers have become yet more popular and are growing more and taller than ever. A new efficient structural system for skyscrapers has been proposed by Tyréns AB, called the Tubed Mega Frame. This structural system consists of hollow concrete tubes at the perimeter of the building. Since this structural system has not yet been used in any skyscraper several aspects have still not been studied or investigated. An important aspect having an impact on the system’s competitiveness compared to traditional structural systems is how a skyscraper using this new structural system could be built. This thesis treats the construction methodology of Tubed Mega Frame structures. The construction methodology of a prototype building is evaluated to connect the findings to a plausible real project. Building very tall concrete structures sets a lot of demands on the concrete used and having an effective construction is essential. The elastic modulus of the concrete has been identified as one of the most important concrete properties why this topic has been studied. Comparisons of the formulas of different codes for estimating the elastic modulus have been made to see what elasticity can be achieved. Concrete recipes that have been used in already built skyscrapers have been reviewed to see what elastic moduli are feasible to reach and expect. Pumping concrete to high levels sets demands on the concretes flowability and self-compacting concrete is necessary to use. Ways of improving the concrete properties are also studied. All studies show that the Tubed Mega Frame structural system would be possible to construct with today’s concrete and pumping technology even though improvements can be expected from future development in concrete technology. As most skyscrapers that are built today, a Tubed Mega Frame structure would preferably be built with a self-climbing formwork system rising one level at a time. From a review of available construction methodologies, the thesis shows that these systems would be applicable on a Tubed Mega Frame structure with minor adaptions of the systems. The floor cycle time, i.e. the time it takes to complete an entire floor before proceeding to the next level, has a significant importance in determining the construction time of a skyscraper. For this reason a floor cycle with all activities related to the structural system and their sequences have been developed for the prototype building. By determining all the relations that are between activities and using productivities for estimating their durations it has been possible to evaluate the time it would take to complete a standard floor. By the use of Microsoft Project the duration of a stated average floor cycle has been estimated to a little more than 4 days.Som en reaktion på att allt fler människor bor i städer har skyskrapor kommit att växa sig allt fler och högre. Traditionellt har skyskrapor oftast utnyttjat någon form av kärna som stomsystem vilken upptar stor yta av våningsplanen. Som en möjlig metod att göra skyskrapors stomsystem effektivare har Tyréns utvecklat det nya stomsystemet Tubed Mega Frame. Då detta bärande system ännu inte har använts i någon skyskrapa är det ett flertal aspekter som inte har blivit studerade och undersökta. En viktig aspekt som är av stor vikt för systemets konkurrenskraft gentemot mer traditionella system är hur det skulle gå till att bygga en skyskrapa som använder detta nya stomsystem. Det här examensarbetet behandlar byggnationsmetodiken för Tubed Mega Frame. Byggnationen av en prototypbyggnad som använder detta system utvärderades för att koppla resultaten till en möjlig verklig byggnad. Att bygga väldigt höga konstruktioner i betong ställer stora krav på betongen som används, och att ha en effektiv byggnation är också av stor vikt. Betongens elasticitetsmodul har identifierats som en av de viktigaste egenskaperna för betongen och därför har detta område studerats djupare. En jämförelse av hur olika normer beräknar elasticitetsmodulen har gjorts och vilka elasticitetsmoduler det ger. De betongsammansättningar som har använts i tidigare skyskrapebyggande har studerats för att se vilka elasticitetsmoduler som kan förväntas. Att pumpa betong till höga höjder ställer stora krav på betongens pumpbarhet. För att göra detta möjligt är det nödvändigt att använda självkompakterande betong. Vilka olika sätt som finns tillgängliga för att styra betongens egenskaper har också studerats. Undersökningarna visar på att det skulle kunna vara möjligt att med dagens betong och pumpteknologi bygga en skyskrapa som använder Tubed Mega Frame som bärande system. Med framtida framsteg inom betongteknologi kan man även förvänta att bättre lämpad teknik kommer att utvecklas. En skyskrapa med stomsystemet Tubed Mega Frame skulle liksom de flesta av dagens skyskrapor lämpligtvis byggas med hjälp av självklättrande formsystem, och därigenom bygga en våning i taget. Studier av teknik och byggnationsmetoder som finns tillgängliga idag har visat på att dagens teknik skulle vara möjliga att applicera på Tubed Mega Frame med endast mindre justeringar. Det som har ett stort inflytande på byggtiden av en skyskrapa är våningscykeltiden, d.v.s. den tid det tar att bygga en våning innan det är möjligt att fortsätta på nästa. Av denna anledning har en våningscykel med alla relevanta moment som ingår blivit bestämd och utvärderad för prototypbyggnaden. Genom att ha klargjort alla relationer mellan olika aktiviteter och den tid de tar att utföra har det varit möjligt att utvärdera den tid en hel våningscykel skulle ta. Med hjälp av Microsoft Project har en våningscykel för en våning som bedömts som representativ för hela prototypbyggnaden kommit att ta drygt fyra dygn.
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Durucan, Cengizhan. "Seismic Retrofitting Of Reinforced Concrete Buildings Using Steel Braces With Shear Link." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610956/index.pdf.
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The catastrophic damage to the infrastructure due to the most recent major earthquakes around the world demonstrated the seismic vulnerability of many existing reinforced concrete buildings. Accordingly, this thesis is focused on a proposed seismic retrofitting system (PSRS) configured to upgrade the performance of seismically vulnerable reinforced concrete buildings. The proposed system is composed of a rigid steel frame with chevron braces and a conventional energy dissipating shear link. The retrofitting system is installed within the bays of a reinforced concrete building frame. A retrofitting design procedure using the proposed seismic retrofitting system is also developed as part of this study. The developed design methodology is based on performance-based design procedure. The retrofitting design procedure is configured to provide a uniform dissipation of earthquake input energy along the height of the reinforced concrete building. The PSRS and a conventional retrofitting system using squat infill shear panels are applied to an existing school and an office building. Nonlinear time history analyses of the buildings in the original and retrofitted conditions are conducted to assess the efficiency of the PSRS. The analyses results revealed that the PSRS can efficiently alleviate the detrimental effects of earthquakes on the buildings. The building retrofitted with PSRS has a more stable lateral force-deformation behavior with enhanced energy dissipation capability than that of the one retrofitted with squat infill shear panels. For small intensity ground motions, the maximum inter-story drift of the building retrofitted with the PSRS is comparable to that of the one retrofitted with squat infill shear panels. But for moderate to high intensity ground motions, the maximum inter-story drift of the building retrofitted with the PSRS is considerably smaller than that of the one retrofitted with squat infill shear panels.
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Jarvis, Wesley James. "The effect of seismic activity on reinforced concrete frame structures with infill masonry panels." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86554.
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Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Certain regions within the Western Cape Province are at risk of a moderate intensity earthquake. It is therefore crucial that infrastructure in these areas be designed to resist its devastating effect. Numerous types of structural buildings exist in these seismic prone areas. The most common types are either reinforced concrete framed buildings with masonry infill or unreinforced masonry buildings. Many of these buildings predate the existence of the first loading code of 1989 which provided regulations for seismic design. The previous code was superseded in 2010 with a code dedicated to providing guidelines for seismic design of infrastructure. A concern was raised whether these buildings meet the requirements of the new code. A numerical investigation was performed on a representative reinforced concrete framed building with masonry infill to determine whether the building meets the new code’s requirements. The results from the investigation show that the stresses at critical points in the columns exceed the codified requirements, thus leading to local failure. After careful review it was discovered that these local failures in the columns will most likely lead to global failure of the building.
AFRIKAANSE OPSOMMING: In sekere streke in die Wes-Kaap bestaan daar risiko van matige intensiteit aardbewings. Dit is dus noodsaaklik dat die infrastruktuur in hierdie gebiede ontwerp word om die vernietigende uitwerking te weerstaan. Gebous met verskillende tipes strukturele uitlegte kom in hierdie gebied voor. Die mees algemene struktuur tipe is gewapende beton-raam geboue met baksteen invol panele sowel as ongewapende baksteen geboue. Baie van hierdie geboue is gebou voor die eerste las-kode van 1989 wat regulasies vir seismiese ontwerp voorsien in gebruik geneem is. Die vorige kode is vervang in 2010 met ’n kode toegewy tot die verskaffing van riglyne vir seismiese ontwerp van infrastruktuur. Kommer het ontstaan of hierdie geboue voldoen aan die vereistes van die nuwe kode. ’n Numeriese ondersoek is uitgevoer op ’n verteenwoordigende gewapende beton geraamde gebou met baksteen panele om te bepaal of die gebou voldoen aan die nuwe kode vereistes rakende sismiese ontwerp. Die resultate van die ondersoek toon dat die spanning op kritieke punte in die kolomme die gekodifiseerde vereistes oorskry, wat tot plaaslike faling lei. Na verdere onderssoek is dit bepaal dat die plaaslike faling in die kolomme waarskynlik tot globale faling van die gebou sal lei.
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Tan, Mustafa Tumer. "Seismic Strengthening Of A Mid-rise Reinforced Concrete Frame Using Cfrps: An Application From Real Life." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610562/index.pdf.
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SEISMIC STRENGTHENING OF A
MID-RISE REINFORCED CONCRETE FRAME
USING CFRPs: AN APPLICATION FROM REAL LIFE
Tan, Mustafa Tümer 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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Ramamoorthy, Sathish Kumar. "Seismic fragility estimates for reinforced concrete framed buildings." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4937.
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Gravity load designed (GLD) reinforced concrete (RC) buildings represent a common
type of construction in the Mid-America Region. These buildings have limited lateral
resistance and are susceptible to story mechanisms during earthquake loading. Fragility
estimates are developed to assess the seismic vulnerability of GLD RC buildings in the
Mid-America Region. Fragility is defined as the conditional probability of reaching or
exceeding a performance level for a given earthquake intensity measure.
Five sample buildings of various story heights (1, 2, 3, 6, and 10 stories) are used to
represent generic RC frame buildings of 1 to 10 stories tall. A Bayesian methodology is
used to develop probabilistic demand models to predict the maximum inter story drift
given the spectral acceleration at the fundamental period of the building. The unknown
parameters of the demand models are estimated using the simulated response data
obtained from nonlinear time history analyses of the structural models for a suite of
synthetic ground motions, developed for Memphis, Tennessee. Seismic structural
capacity values are selected corresponding to the performance levels or damage states as
specified in FEMA-356 and as computed by nonlinear pushover analyses.
For the sample buildings, fragility estimates are developed using the predicted drift
demands and structural capacity values. Confidence bounds are developed to represent
the epistemic uncertainty inherent in the fragility estimates. In addition, bivariate fragility estimates, formulated as a function of spectral acceleration and the fundamental
building period, are developed from the fragility estimates of the individual buildings.
The bivariate fragilities can be used to quantify the seismic vulnerability of GLD RC
frame buildings of 1 to 10 stories. Using the Bayesian approach, a framework is
developed to update the analytical fragility estimates using observed damage data or
experimental test data. As an illustration of the updating framework, the analytical
bivariate fragility estimates for the sample buildings in the Mid-America Region are
updated using the damage data obtained from 1994 Northridge, California earthquake.
Furthermore, to investigate and demonstrate the increase in seismic performance
of the GLD RC frame buildings, the columns of the 2 and 3 story buildings are
retrofitted by column strengthening. Fragility estimates developed for the retrofitted
buildings show the effectiveness of the retrofit technique by the improved seismic
performance of GLD RC frame buildings.
25
Rackham, James William. "The design of haunched composite beam frames for buildings." Thesis, City University London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358221.
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26
Marshall, John Richard. "A comparative study of analysis techniques for multistory concrete frames." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/19035.
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27
Baradaran, Shoraka Majid. "Collapse assessment of concrete buildings : an application to non-ductile reinforced concrete moment frames." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45000.
Full textAbstract:
Existing reinforced concrete buildings lacking details for ductile response during earthquake shaking represent prevalent construction type in high seismic zones around the world. Seismic rehabilitation of these existing buildings plays an important role in reducing urban seismic risk; however, with the massive inventory of existing concrete buildings and high costs of seismic rehabilitation, it is necessary to start by identifying and retrofitting those buildings which are most vulnerable to collapse.
The collapse of most non-ductile concrete buildings will be controlled by the loss of support for gravity loads prior to the development of a side-sway collapse mechanism. “Gravity load collapse” may be precipitated by axial-load failure of columns, punching-shear failure of slab-column connections, or axial-load failure beam-column joints. In this dissertation, system-level collapse criteria are developed and implemented in a structural analysis platform to allow for a more accurate detection of collapse in these existing moment frames.
Detailed models for primary components, which may precipitate gravity-load collapse of the concrete moment frame, are first required to achieve this objective and develop the collapse assessment framework. An analytical model based on mechanics is developed to reliably capture the lateral load–deformation response of a broad range of reinforced concrete columns with limited ductility due to degradation of shear resistance, either before or after flexural yielding.
The robust collapse performance assessment could be used for many structural applications. In this dissertation, it is used to identify collapse indicators, design and response parameters that are correlated with “elevated” collapse probability. The collapse assessment framework is also used to identify the relative collapse risk of different rehabilitation techniques. Finally, the framework is used to estimate the impact of collapse criteria on the expected financial losses for existing concrete frame buildings in high seismic zones.
This dissertation includes important contributions to (1) modeling techniques for components in existing concrete frames through the development of a mechanical model for existing concrete columns, (2) development of system-level collapse criteria, and (3) application of collapse fragilities in defining collapse indicators, improving loss estimation of existing concrete frames, and differentiating the collapse performances of existing and retrofitted concrete frames.
28
Lee, Seungjea. "Robustness of reinforced concrete framed building at elevated temperatures." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/robustness-of-reinforced-concrete-framed-building-at-elevated-temperatures(db90ad82-86b5-4ba3-9ef1-42e7004b4b34).html.
Full textAbstract:
This thesis presents the results of a research programme to investigate the behaviour and robustness of reinforced concrete (RC) frames in fire. The research was carried out through numerical simulations using the commercial finite element analysis package TNO DIANA. The main focus of the project is the large deflection behaviour of restrained reinforced concrete beams, in particular the development of catenary action, because this behaviour is the most important factor that influences the frame response under accidental loading. This research includes four main parts as follows: (1) validation of the simulation model; (2) behaviour of axially and rotationally restrained RC beams at elevated temperatures; (3) derivation of an analytical method to estimate the key quantities of restrained RC beam behaviour at elevated temperatures; (4) response and robustness of RC frame structures with different extents of damage at elevated temperatures. The analytical method has been developed to estimate the following three quantities: when the axial compression force in the restrained beam reaches the maximum; when the RC beams reach bending limits (axial force = 0) and when the beams finally fail. To estimate the time to failure, which is initiated by the fracture of reinforcement steel at the catenary action stage, a regression equation is proposed to calculate the maximum deflections of RC beams, based on an analysis of the reinforcement steel strain distributions at failure for a large number of parametric study results. A comparison between the analytical and simulation results indicates that the analytical method gives reasonably good approximations to the numerical simulation results. Based on the frame simulation results, it has been found that if a member is completely removed from the structure, the structure is unlikely to be able to develop an alternative load carrying mechanism to ensure robustness of the structure. This problem is particularly severe when a corner column is removed. However, it is possible for frames with partially damaged columns to achieve the required robustness in fire, provided the columns still have sufficient resistance to allow the beams to develop some catenary action. This may be possible if the columns are designed as simply supported columns, but have some reserves of strength in the frame due to continuity. Merely increasing the reinforcement steel area or ductility (which is difficult to do) would not be sufficient. However, increasing the cover thickness of the reinforcement steel to slow down the temperature increase is necessary.
29
Guo, Mingchao. "Finite element analysis of confined concrete in building frame components and joints." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264396.
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30
Samman, Tamim Abdulhadi. "Indeterminate reinforced concrete frames subjected to inelastic cyclic deformation." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184307.
Full textAbstract:
Four full-size statically indeterminate reinforced concrete frames with two symmetrical bays were tested to obtain sufficient data to evaluate the adequacy of the current ACI-ASCE Committee 352 design recommendations, as well as to determine whether a relaxation of some of the limits in these guidelines can be justified. Each specimen contained three 8.5-foot-long columns, connected at mid-height by two 9-foot-long beams. Initially, a constant axial load was applied to each column. The specimens were then subjected to a displacement-controlled loading schedule to simulate the type of displacements a frame may experience during a severe earthquake. In designing the specimens, the latest recommendations of the ACI-ASCE Committee 352 and the ACI building code ACI 318-83 were satisfied except for the following modifications: (1) the flexural strength ratio (M(R)) in the second specimen was reduced from 1.4 to 1.2, (2) the shear-stress factors (γ) in the joints of the third specimen were increased from 12 and 15 to 15 and 20 for the exterior and interior joints respectively, and (3) the number of the transverse reinforcements inside the right exterior joint in the fourth specimen was reduced from 4 to 2 sets of hoops. The conclusion inferred from the results indicate that for drift levels within the elastic range, the elongations and the rotations of the beam regions near the faces of the columns, in addition to the joint shear strains, were not affected by the design values for the primary variables in the last three specimens. For larger excursions into the inelastic range, the relaxation of the current Committee 352 design recommendations in the last three specimens not only showed a significant effect in reducing the elongations and the rotations of the beams, or in increasing the joint shear strains but led to lower energy dissipation of the specimens. Consequently, the current design guidelines by the ACI-ASCE Committee 352 yield statically indeterminate frames which exhibit sufficient ductility.
31
Miratashi, Yazdi Seyed Mansoor. "Robustness of steel framed buildings with pre-cast concrete floor slabs." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/robustness-of-steel-framed-buildings-with-precast-concrete-floor-slabs(7004a673-cf6c-4d22-a00e-34c6be6bb6a0).html.
Full textAbstract:
Following some incidents in high-rise buildings, such as Ronan Point London 1968, in which collapse of a limited number of structural elements progressed to a failure disproportionate to the initial cause, consideration of robustness was introduced in British Standard. The main method of preventing progressive collapse for providing robustness to steel framed buildings with precast concrete floor slabs focuses on the allowable tying forces that the reinforcement in between the slabs and in hollowcores should carry. However there are uncertainties about the basis of the practical rules associated with this method. This thesis presents the results of numerical and analytical studies of tie connection behaviour between precast concrete floor slabs (PCFS). It is shown that under current design regulations the tie connection is not able to resist the accidental load limit applied on the damaged floor slabs. By establishing the capability of a finite element model to depict and predict the behaviour of concrete members in situations such as arching and catenary action against several experimental tests, an extensive set of parametric studies was conducted in order to identify the effective parameters in enhancing the resistance of the tie connection between PCFSs. These parameters include: tie bar diameter, position, length, yield stress and ultimate strain; the slab’s height, length; and the compressive strength of the grouting concrete in between the slabs that encases the tie bar. Recommendations are made based on the findings of this parametric study in order to increase the resistance of the tie connection. Based on the identified effective parameters in the parametric study a predictive analytical relationship is derived which is capable of determining the maximum vertical displacement and load that the tie connection is able to undergo. This relationship can be used to enable the connection to capture the accidental limit load on a damaged slab. The identified parameters are examined in a three dimensional finite element model to assess their effect when columns of the structure are lost in different locations such as an edge, corner or internal column. Based on the findings of this study methods for improving the connections performance are presented. Also the effect of alternative transverse tying method is evaluated and it is concluded that although this kind of tie increases the load carrying capacity of the connection, its effect on the catenary action is not significant.
32
LA, MAZZA DARIO. "Numerical models for the robustness assessment of reinforced concrete framed buildings." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2712599.
Full textAbstract:
Cast in situ reinforced concrete frame is one of the most common options for civil buildings. Although earliest common usages of this solution date back to second half of 19th century, research activity is constantly developing to investigate several aspects, especially about nonlinear behaviour of reinforced concrete structures.
Structural robustness of buildings is actually one of the key issues faced by the international scientific community. This expression is used to indicate a desirable property of a structure that allows it to withstand an accidental event, preventing progressive and/or disproportionate collapse.
Interest in this topic has been growing rapidly after the collapse of Ronan Point Apartment Tower in Newham, East London, in 1968, when a gas explosion destroyed a loadbearing concrete panel causing the collapse of an entire corner of the building.
Although the issue of progressive collapse of multi-storey frames has been widely studied in the last decades, according to the literature review, the actual structural response after a localised failure has not yet been fully understood. Besides, many design guidelines for preventing progressive collapse denote a lack of adequate theoretical supports.
Several technics have been developed to evaluate the response after an accidental situation. In Europe, EN1991-1-7 has introduced the notional removal design strategy. This approach establishes that a building should be checked to ensure that upon the notional removal of each column or each beam supporting a column, or any nominal section of load-bearing wall, one at a time in each storey of the building, the structure remains stable exhibiting only localised failure.
Currently one of the main solution to ensure robustness consists in tying together structural members by using continuous reinforcement. In this context, the designer is required to evaluate the global structural response, then the role played by the floor-system becomes crucial. However, this operation involves longer times for modelling and analyses.
The study here presented is articulated through several points. The initial intent is to develop simplified models of the floor-system able to simulate its behaviour, to obtain accurate results through a more efficient modelling. Different numerical models will be presented. These will focus on distinct simplification levels, depending on the finite elements adopted. The codes used for nonlinear numerical analyses have been previously tested and validated on experimental tests on 2D and 3D specimens and both static and dynamic analyses.
The second aim is to evaluate the effectiveness of different floor-system typologies on the global behaviour of reinforced concrete frames. Two typical reinforced concrete solutions are tested: the first exploits a bidirectional slab, while the second uses monodirectional joists with a collaborating slab.
To compare the results, a structure with features common to most of the reinforced concrete buildings has been chosen as reference test. The considered scenarios involve the removal of four distinct columns: two internal ones with different boundary conditions, an edge column and a corner column, all the elements are placed at the ground floor level.
The third aim is to evaluate the influence of several parameters on global response, to identify their possible influence on the phenomenon and to highlight which among these have a determining impact on the structural response. The factors investigated are: primary beams depth, columns depth, presence of bracing systems, continuous reinforcement amount and seismic detailing.
The achieved results provide precise information on the overall structural behaviour, highlighting the key role played by certain factors such as the percentage of continuous reinforcement in the beams and the importance of seismic detailing. At the same time the analyses have highlighted the marginal influence exerted by other parameters like the stiffening contribution given by a bracing system or stiffer columns, whose effects may be considered negligible.
33
Mohamed, Sherif Ali Mohtady. "Behaviour of sleeved bolt connections in precast concrete building frames." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315403.
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Abou-Elfath, Hamdy Mohamed. "Rehabilitation of nonductile reinforced concrete buildings using steel systems /." *McMaster only, 1998.
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35
Matthews, Timothy William. "Explosive testing to assess dynamic load redistribution in a reinforced concrete frame building." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31999.
Full textAbstract:
Guidelines have been developed in the United States to assist in the design of buildings resistant to progressive collapse. These guidelines outline several methods for considering the effects of dynamic amplification on load redistribution following sudden member failure in a structure. Previous analytical studies have been performed to evaluate the consistency of these guidelines, but very little testing has been conducted to verify the guidelines and analytical work performed to date. This study investigates the dynamic load redistribution occurring in a field test on a two-storey reinforced concrete frame specimen. The test consisted of removing a column with explosives and recording the deformations of the remaining columns in the structure. The explosives removed the load-carrying capacity of the column but also exerted an upward force on the structure. Observations from the test suggest the building frame remained linear-elastic. A linear analytical model of the test specimen was developed in ETABS. This model effectively captured the response of the structure during testing. The model was used to examine the response of the test specimen due to gravity load redistribution alone, as well as the total response of the structure, including the effects of the upward force from the explosion. A dynamic amplification factor of 1.89 was observed for the columns where the majority of the gravity load redistributed during in the experimental test. This value supports the maximum dynamic amplification of 2.0 proposed for linear structures by previous research and progressive collapse assessment guidelines. The response at these columns was dominated by one mode of vibration. At columns where less steady-state load was redistributed, dynamic amplification factors much greater than 2.0 were observed, although the absolute peak axial force increases were relatively small. Higher modes influenced by cantilevers along one side of the structure contributed significantly to the peak demands at these locations. The upward explosive force magnified the peak demands on the structure from gravity load redistribution by as much as 68%. The upward explosive force was also observed to act unsymmetrically on the structure. These effects must be considered when considering column failures from explosives installed inside the member.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
36
Parsa, Amanullah. "EFFECT OF BUILDING ORIENTATION ON STRUCTURAL RESPONSE OF REINFORCED CONCRETE MOMENT RESISTING FRAME STRUCTURES." OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2698.
Full textAbstract:
In time history analysis of structures, the geometric mean of two orthogonal horizontal components of ground motion in the as-recorded direction of sensors, have been used as measure of ground motion intensity prior to the 2009 NEHRP provision. The 2009 NEHRP Provisions and accordingly the seismic design provisions of the ASCE/SEI 7-10, modified the definition of ground motion intensity measure from geometric mean to the maximum direction ground motion, corresponding to the direction that results in peak response of the oscillator. Maximum direction response spectra are assumed to envelope the range of maximum possible responses over all nonredundant rotation angles. Two assumptions are made in the use maximum ground motion as the intensity measure: (1) the structure’s strength and stiffness properties are identical in all directions and (2) azimuth of the maximum spectral acceleration coincides with the one of the principal axes of the structure. The implications of these assumptions are examined in this study, using 3D computer models of multi-story structures having symmetric and asymmetric layouts and elastic vibration period of 0.2 second and 1.0 second subjected to a set of 25 ground-motion pairs recorded at a distance of more than 20 km from the fault. The influence of the ground-motion rotation angle on structural response (here lateral displacement and story drift) is examined to form benchmarks for evaluating the use of the maximum direction (MD) ground motions. The results of this study suggest that while MD ground motions do not always result in largest structural response, they tend to produce larger response than the as-recorded ground motions. On the other hand, more research on non-linear seismic time history analysis is recommended, especially for asymmetric layout plan buildings.
37
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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Tuken, Ahmet. "Quantifying Seismic Design Criteria For Concrete Buildings." Phd thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/12604907/index.pdf.
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The amount of total and relative sway of a framed or a composite (frame-shear wall) building is of utmost importance in assessing the seismic resistance of the building. Therefore, the design engineer must calculate the sway profile of the building several times during the design process.
However, it is not a simple task to calculate the sway of a three-dimensional structure. Of course, computer programs can do the job, but developing the three-dimensional model becomes necessary, which is obviously tedious and time consuming.
An easy to apply analytical method is developed, which enables the determination of sway profiles of framed and composite buildings subject to seismic loading. Various framed and composite three-dimensional buildings subject to lateral seismic loads are solved by SAP2000 and the proposed analytical method. The sway profiles are compared and found to be in very good agreement. In most cases, the amount of error involved is less than 5 %.
The analytical method is applied to determine sway magnitudes at any desired elevation of the building, the relative sway between two consecutive floors, the slope at any desired point along the height and the curvature distribution of the building from foundation to roof level.
After sway and sway-related properties are known, the requirements of the Turkish Earthquake Code can be evaluated and / or checked.
By using the analytical method, the amount of shear walls necessary to satisfy Turkish Earthquake Code requirements are determined. Thus, a vital design question has been answered, which up till present time, could only be met by rough empirical guidelines.
A mathematical derivation is presented to satisfy the strength requirement of a three-dimensional composite building subject to seismic loading. Thus, the occurrence of shear failure before moment failure in the building is securely avoided.
A design procedure is developed to satisfy the stiffness requirement of composite buildings subject to lateral seismic loading. Some useful tools, such as executable user-friendly programs written by using &ldquoBorland Delphi&rdquo
, have been developed to make the analysis and design easy for the engineer. A method is also developed to satisfy the ductility requirement of composite buildings subject to lateral seismic loading based on a plastic analysis. The commonly accepted sway ductility of &
#956
&
#916
=5 has been used and successful seismic energy dissipation is thus obtained.
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Hertanto, Eric. "Seismic Assessment of Pre-1970s Reinforced Concrete Structure." Thesis, University of Canterbury. Civil Engineering, 2005. http://hdl.handle.net/10092/1120.
Full textAbstract:
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.
40
Zimos, D. K. "Modelling the post-peak response of existing reinforced concrete frame structures subjected to seismic loading." Thesis, City, University of London, 2017. http://openaccess.city.ac.uk/18531/.
Full textAbstract:
Structural members of reinforced concrete (R/C) buildings designed according to older, less stringent seismic codes are often vulnerable to shear or flexure-shear failure followed by axial failure. Thus, such substandard R/C structures are susceptible to vertical collapse, which pertains to the exceedance of vertical resistance of columns and connecting beams and can lead to the whole structure – or a substantial part of it – undergoing collapse. The largest database of shear and flexure-shear critical R/C columns cycled well beyond the onset of shear failure and/or up to the onset of axial failure is compiled and empirical relationships are developed for key parameters affecting the response of such members after the initiation of shear failure. A novel shear hysteresis model is proposed employing these relationships, based on experimental observations that deformations after the onset of shear failure tend to concentrate in a specific member region. A computationally efficient finite element model of the member-type is proposed, using the above shear hysteretic model and combining it with displacements arising from flexural and bond-slip deformations to get the full lateral force-lateral displacement response. It accounts for the interaction between flexural and shear deformations inside the potential plastic hinges, the distribution of flexural and shear flexibility along the element, as well as the location and extent of post-peak shear damage, without relying on assumptions about the bending moment distribution and avoiding shortcomings of previous beam-column models pertinent to numerical localisation. Thus, the full-range hysteretic response of substandard R/C elements can be predicted up to the onset of axial failure subsequent to shear failure with or without prior flexural yielding, while simultaneously accounting for potential flexural and anchorage failure modes. The proposed model is implemented in a finite element structural analysis software and its predictive capabilities are verified against quasi-static cyclic and shake-table test results of column and frame specimens. The model is shown to be sufficiently accurate not only in terms of total response, but more crucially in terms of individual deformation components. Overall, it is believed that the accuracy, versatility and simplicity of this model make it a valuable tool in seismic analysis of complex substandard R/C buildings. An experimental investigation of shear and flexure-shear critical R/C elements is carried out with the aim of independently validating the beam-column model. Furthermore, an opportunity is provided to verify the model’s underlying assumptions, which is of paramount importance for the reliability of its analytical predictions. The experiments were designed in such a manner as to investigate the effect of vertical load redistribution from axially failing members on the lateral post-peak response of neighbouring columns.
41
Jayasooriya, Jayasooriya Hevavitharanage Aruna Ruwan. "Vulnerability and damage analysis of reinforced concrete framed buildings subjected to near field blast events." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/67925/1/Ruwan_Jayasooriya_Thesis.pdf.
Full textAbstract:
Terrorists usually target high occupancy iconic and public buildings using vehicle borne incendiary devices in order to claim a maximum number of lives and cause extensive damage to public property. While initial casualties are due to direct shock by the explosion, collapse of structural elements may extensively increase the total figure. Most of these buildings have been or are built without consideration of their vulnerability to such events. Therefore, the vulnerability and residual capacity assessment of buildings to deliberately exploded bombs is important to provide mitigation strategies to protect the buildings' occupants and the property. Explosive loads and their effects on a building have therefore attracted significant attention in the recent past.
Comprehensive and economical design strategies must be developed for future construction. This research investigates the response and damage of reinforced concrete (RC) framed buildings together with their load bearing key structural components to a near field blast event. Finite element method (FEM) based analysis was used to investigate the structural framing system and components for global stability, followed by a rigorous analysis of key structural components for damage evaluation using the codes SAP2000 and LS DYNA respectively. The research involved four important areas in structural engineering. They are blast load determination, numerical modelling with FEM techniques, material performance under high strain rate and non-linear dynamic structural analysis. The response and damage of a RC framed building for different blast load scenarios were investigated. The blast influence region for a two dimensional RC frame was investigated for different load conditions and identified the critical region for each loading case. Two types of design methods are recommended for RC columns to provide superior residual capacities. They are RC columns detailing with multi-layer steel reinforcement cages and a composite columns including a central structural steel core. These are to provide post blast gravity load resisting capacity compared to typical RC column against a catastrophic collapse. Overall, this research broadens the current knowledge of blast and residual capacity analysis of RC framed structures and recommends methods to evaluate and mitigate blast impact on key elements of multi-storey buildings.
42
Nyberg, Fanny. "Material choices for the building frame : Effects on the accomplishment of the Sustainable Development Goals’ targets." Thesis, Mittuniversitetet, Institutionen för ekoteknik- och hållbart byggande, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39126.
Full textAbstract:
Potential synergy effects and conflicts, so-called interactions, between a climate action that aims to mitigate the climate impact and five targets of the Sustainable Development Goals are identified in this study. The climate action is Conscious material choices for the frame, and the materials assessed are climate improved concrete and domestic wood. Standard concrete is used as the business as usual scenario. A pre-school building is used as an example building to demonstrate the difference in the climate impact of a frame made from the two materials assessed in the study. Life cycle assessments (LCA) of the frames shows that the domestic wood frame has a lower climate impact than the climate improved concrete frame.Two methods are used in this study. The first method is making an LCA for transportation of the materials assessed to see the environmental impact, and there is one scenario for each material where the transportation method is by a truck and one that is by train. The second method used for the study is a goal interaction scoring-method from “A draft framework for understanding SDG interactions” by Nilsson et al. (2016) that gives the interactions a score based on specific criteria. The scores are visualised in a colour coordinated matrix. The interactions generate synergies if the sums of the scores in the matrix are positive and will likely help accomplish the target. If the sums of the scores in the matrix are negative, it indicates that there are conflicts that could endanger the possibilities to reach the target.LCA of the transport scenarios shows that when the transportation distance is long, the climate impact is lowest when transporting as much as possible of the materials by train. Transporting the domestic wood for the frame by train (for longer distances) has a lower climate impact than transporting the climate improved concrete. For shorter distances, there is not a significant difference between transportation by truck or by train. The climate improved concrete gets score 0, meaning that there are neither positive nor negative interactions for the chosen material for the frame. The domestic wood gets the score +8, which indicates that there are synergies. Both the climate improved concrete and the domestic wood should not interfere with the accomplishment of the Sustainable Development Goal’s targets. However, the domestic wood for the frame generates more synergies and by choosing the domestic wooden frame for a building using a train as a transportation of the material when possible has the lowest environmental impact of the assessed materials for the frame.2020-06-08
43
Celik, Ozan Cem. "Probabilistic Assessment of Non-Ductile Reinforced Concrete Frames Susceptible to Mid-America Ground Motions." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16208.
Full textAbstract:
The infrequent nature of earthquakes in the Central and Eastern United States (CEUS), and the fact that none with intensity comparable to the New Madrid sequence of 1811 12 or the Charleston earthquake of 1886 has occurred in the past century, have caused the earthquake hazard in the region to be ignored until quite recently. The seismic performance of reinforced concrete (RC) frames in the CEUS, which have primarily been designed for gravity load effects, is expected to be deficient when subjected to earthquakes that are judged, in recent seismological research, as being plausible in the New Madrid Seismic Zone (NMSZ). The objective of this study is to develop a set of probability-based tools for efficient uncertainty analysis and seismic vulnerability and risk assessment of such gravity load designed (GLD) RC frames and to use these tools in evaluating the seismic vulnerability of RC frames that are representative of the building inventory in Memphis, TN the largest population center close to the NMSZ.
Synthetic earthquake ground motions for the CEUS that are available from two different Mid-America Earthquake (MAE) Center projects were used in the finite element-based simulations for determining the seismic demand on the GLD RC frames by nonlinear time history analysis (NTHA). A beam-column joint model was developed to address the deficiencies in the joints of GLD frames and was incorporated in the finite element structural models. Seismic fragilities were derived for low-, mid-, and high-rise GLD RC frames. Various sources of uncertainty were propagated through the analysis, and their significance for fragility assessment was examined. These fragilities were used to evaluate the vulnerability of the RC frame inventory in Memphis, TN with regard to performance-based design objectives, defined in terms of performance levels associated with reference earthquake hazard levels. This performance appraisal indicated that GLD RC frames do not meet the life safety and collapse prevention performance objectives that are found in recent building codes and guidelines for performance-based earthquake engineering.
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Wan, Chi Kin. "Time history analysis and optimal drift design of multi-storey concrete building structures under seismic excitations /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20WAN.
Full textAbstract:
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 127-131). Also available in electronic version. Access restricted to campus users.
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Pezic, Nedim, and Saif Al-Omari. "Klimatförbättrad betong- eller trästomme i en byggnad : - Vilket alternativ är mest fördelaktigt ur ett livscykelperspektiv." Thesis, Jönköping University, JTH, Byggnadsteknik och belysningsvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-53969.
Full text
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Ibrahim, Josif, and Ahmad Kateesh. "Comparison of two different materials on frame systems with focus on life cycle analysis." Thesis, KTH, Byggteknik och design, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278747.
Full textAbstract:
The structural engineer should not only be able to perform design calculations but also findmore efficient solutions for building parts. The purpose of this thesis is to redesign a concreteframe for a house (an apartment building) into a light frame with steel columns andcompartment walls, as well as perform a life cycle analysis for materials on both frames anddetermine the frame with the lowest environmental impact.The result shows that the lightweight frame with steel columns and compartment walls is amuch better choice for the environment as it stands only for 60 000 kg CO2e compared toconcrete frame which stands for 163 000 kg / CO2e. The steel frame emits about 60% lessemissions than the concrete frame.By optimizing steel columns in the upper floors and choosing smaller columns led to ten tonsless mass of steel and less emissions by 15 000 kg / CO2e.The selected compartment wall has a thickness of 309 mm which is 6 mm thicker than theexisting wall which results in a reduction of the area of house by 6 square meters throughoutthe house which can be expensive depending on the location of the house.In conclusion, the material concrete is good when it is needed due to requirements on fire,noise, and durability but also less suitable when not needed. In this case, it is useless with thematerial concrete as the outer wall and can therefore be replaced by a steel columns andcompartment wall instead.Konstruktören ska inte endast kunna utföra beräkningar utan även hitta effektivare lösningar till byggnadsdelar. Syftet med detta examensarbete är att dimensionera om en betongstomme för ett flerbostadshus till en lättstomme med stålpelare och utfackningsväggar samt även utföra en livscykelanalys för material på stommar och bestämma stommen med lägst miljöpåverkan.Resultatet visar att lättstomme med stålpelare och utfackningsvägg är ett mycket bättre val för miljön då står den för 60 000 kg/CO2e jämfört med betongstomme som står för 163 000 kg/CO2e. Stålstommen släpper ut ungefär 60 % mindre utsläpp än betongstommen.Optimering av stålpelare i övre plan och att välja mindre pelare ledde till tio ton mindre massa stål och även mindre utsläpp på 15 000 kg/CO2e.Den valda utfackningsväggen har tjocklek 309 mm vilket är 6 mm tjockare än den befintliga väggen som i sin tur resulterar i en areaförlust med 6 kvadratmeter i hela huset vilket kan vara dyrt beroende på husets läge.Som slutsats är att materialet betong är bra när det behövs på grund av till exempel brand, ljud och beständighet men även mindre lämpligt när det inte behövs. I detta fall är det mindre lämpligt med materialet betong som yttervägg och man kan därför använda utfackningsvägg med stålpelare istället.
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MARANTOU, LYDIA FOTEINI, and PAULINA CHOJNICKA. "Global analysis of a tubed structural system for an inclined slender tall building." Thesis, KTH, Betongbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209697.
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Building engineering is called upon to keep up with the pace and challenges of modern design, which aims not only to build higher and greener, but also to fulfill the demands of the growing population and simple human curiosity. The main purpose of this study was to examine the global behavior of a slender and inclined (V-shaped) 300 m high rise building with different structural systems applied. In order to properly evaluate them, four different parametric studies were conducted. These included determining the appropriate inclination angle and the geometry of a simple beam system and later comparing fourteen different structural systems, namely trusses, diagrids, Tubed Mega Frames and moment frames. Parallel to this, a further investigation was made on a shell and beam element model, in order to assess the simplifications made and to control the obtained results. This study was based on various simulations in Finite Element Analysis programs, primarily ETABS, but also SAP2000 and Autodesk Robot Structural Analysis. The modelling included the definition of geometry and applied loads and results in extracting the desirable forces and deformations. Additionally, the automatic design for structural members was used for the purpose of a comprehensive study of the chosen structural systems. The designed structures were subjected to static analysis (dead, live, wind, seismic load), dynamic analysis (response spectrum and time history function) and nonlinear P-delta effect. A buckling analysis was also performed to determine the modes and associated load factors for buckling. In the end, the structural response in terms of displacement and acceleration was compared. The inclination angle study set the defining angle at 10° from vertical, with respect to the serviceability limit deflection. Comparing alternative truss geometries in a 2D parametric study resulted in the choice of four different systems (X, N, K and W trusses). In the 3D analysis, the chosen truss systems, together with three variations of diagrid systems, and seven Tubed Mega Frames with two moment frame structures were further analyzed. In both groups, the mass and the material of the systems were kept similar and the comparison was basically based on the obtained maximum displacement and natural periods of the buildings. The shell and frame model comparison gave a difference in displacements between 0 and 12%. Finally, the comprehensive study of the Tubed Mega Frame, X truss and diagrid structures showed that these buildings were performing similarly to vertical buildings with a top story displacement within the suggested limits (less than 673 mm). Further investigation should be made concerning the acceleration under synthetic earthquake, which exceeded the suggested norms, as well as the connecting nodes between the trusses and the inclined columns. The outcome of this study implied the possibility of construction and usability of inclined, slender, tall buildings with respect to the Ultimate Limit State and the Service Limit State, as specified in the American standard, ASCE 7-10, and opened new possible issues for further research.
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Deumic, Emina, and Madelaine Hedin. "Utvärdering av skalväggar som byggnadsmetod." Thesis, Linnaeus University, School of Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-6188.
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Granskande av ritningar, tidsplaner och kalkyler för referensprojektet Hus N i Växjö har hjälpt oss kartlägga skalväggars för- och nackdelar. Från intervjuer har vi sedan kunnat se liknelser och skillnader om vad olika yrkesfolk i samma bransch tycker, sedan därifrån dragit slutsatser. Det är inte alltid enkelt att avgöra vilken byggnadsmetod som är att föredra för att projektet ska vara kostnadseffektivt, prefabricerat eller platsbyggd. Faktorer som byggnadens konstruktion, årstid, arbetsmiljö, resurser, tid och kostnad ska ta hänsyns till.
Genom att planera bättre, öka förtillverkningen, skapa en bättre samverkan mellan byggherrar, konsulter, entreprenörer, underentreprenörer och materialleverantörer, så anser man allmänt att man kan öka industrialiseringen av byggandet. Då man kan få kortare byggtider och lägre totalkostnader.
Checking of blueprints, time plans and calculations for the reference project house-N in Växjö have helped us to map double walls' advantages and disadvantages. From interviews, we have seen similarities and difference what different people in same sector think, and how they make their conclusions. It is not always simple to decide the preferable building method in order to make the project cost-effective, prefabricated or suite-built. Factors such as the building's frame, season, work environment, resources, time and cost take considerations' to.
Through better planning, increase of prefabrication and achieving a better collaboration between developers, consultants, contractors, subcontractors and material suppliers, it is generally considered that it may increase the industrialization of the building. Then procurement of shorter construction times and lower overall costs can be achieved
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Murahidy, Alexander Gustav. "Design, construction, dynamic testing and computer modelling of a precast prestressed reinforced concrete frame building with rocking beam-column connections and ADAS elements." Thesis, University of Canterbury. Department of Civil Engineering, 2004. http://hdl.handle.net/10092/2514.
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Following a major earthquake event, essential public amenities such as medical facilities and
transport networks need to remain functional - not only to fulfil their ongoing role in serving
the community but also to cope with the added and immediate demand of a population
affected by a natural disaster. Furthermore, the economic implications of wide spread damage
to housing and commercial facilities should not be discounted. A shift in design approach is
required that is consistent with current trends towards performance based building design. The
present aim is to achieve seismic energy dissipation during the earthquake event, without the
aftermath of damage to structural elements, whilst maintaining design economies.
Structures permitted to rock on their foundations and provide recoverable rotations at the
beam-column interfaces offer significant advantages over those using conventional ductile
detailing. A jointed construction philosophy can be applied whereby structural elements are
connected with unbonded prestressing tendons. Supplemental damping is provided by
replaceable flexural steel components designed to deform inelastically. For this research a
multi-storey test building of one quarter scale has been constructed and tested on an
earthquake simulator at the University of Canterbury. A computer model has been developed
and a set ofpreliminary design procedures proposed.
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Bystedt, Gabriella, and Bernuy Fatima Estrada. "Balance between financial and quality gains in housing production : A study on concrete and wooden frames." Thesis, KTH, Byggteknik och design, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296546.
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With increased demand for housing in Sweden's metropolitan regions, it is of greatimportance to meet the need and build more. The supply of housing is governed byaccess to land and what it costs to build apartment houses. In Sweden, there is ahistory of cartel formation of contractors and at the turn of the millennium, thegovernment invested funds to create increased price transparency in theconstruction sector. Based on this, the purpose of this project is to investigate how itis possible to today produce housing more economically, while maintaining quality.The study is limited to the purchase of prefabricated hollow core and load-bearingwall elements in both concrete and wood. The goal is to be able to compare prices ofthese construction parts between Swedish and foreign suppliers. The foreignsuppliers are limited to the ones operating in the Baltic countries and Poland. Thus, itmust be investigated which of the wooden or concrete frames is most economicallyprofitable, what opportunities there are with international purchases of frameelements and what should be taken into account in international purchases.I och med ökad efterfrågan på bostäder i Sveriges storstadsregioner är det av vikt atti samma takt öka utbudet. Utbudet styrs av tillgång till mark samt vad det kostar attbygga. I Sverige finns en historia av kartellbildning av byggföretag och regeringensatte vid millennieskiftet in medel för att skapa ökad pristransparens inombyggsektorn. Med bakgrund i detta är syftet med examensarbetet att undersöka hurdet idag går att producera bostäder mer ekonomiskt, med bibehållen kvalitet iåtanke. Studien avgränsas till inköp av prefabricerade håldäck och bärandeväggelement i betong respektive trä. Målet är att kunna jämföra priser av dessakonstruktionsdelar mellan svenska och utländska leverantörer. De utländskaleverantörerna avgränsas till att verka inom baltikum och Polen. Således ska detutredas vad utav trä- eller betongstomme som är mest ekonomiskt lönsamt, vilkamöjligheter som finns med internationella inköp av stomelement samt vad som börtas hänsyn till vid internationella inköp.De risker som finns kopplade till just internationella inköp är bland andra risk attprodukten inte stämmer överens med vad som avtalats och leveransförseningar.Logistikrisker begränsas med hjälp av avtal reglerade utifrån det internationellaregelverket Incoterms. Det finns även politiska och valutarelaterade risker medinternationell handel.ISO 9000 är ett kvalitetsledningssystem som ligger till grund för att företag ochorganisationer ska kunna säkerställa att kvaliteten i deras arbete svarar upp motkundens behov och krav. ISO 14000 samlar standarder inom miljöledningssystem.Intervjuer av sex svenska och fem utländska leverantörer om pris och kvalitetsarbetegav intressanta resultat för studien. Samtliga utländska leverantörer är certifierademed ISO 9001 samt ISO 14001. Två av sex svenska bolag har ISO9001-certifieringen och hälften ISO 14001-certifieringen. Att köpa prefabriceradebetongelement är enligt studien inte ekonomiskt lönsammare i utlandet, det är detdäremot att köpa träelement.