Betonarme yüksek yapıların taşıyıcı sistemlerinin incelenmesi ve tüp taşıyıcı sistemli yüksek yapının dinamik hesabı

Ardıç, Hüseyin
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Fen Bilimleri Enstitüsü
Yüksek yapılar, itışaa edildikleri ülkenin inşaat sektörünün yapışma ve özelliklerine göre deği şik malzemelerin daha yaygın kullanımıyla gerçekleştirilirler. Yurdumuzda gerek çeliğin pahalı bir malze me olması gerekse betonarmenin çok yaygın olarak kullanılan bir inşaat malzemesi olması gibi nedenler le yüksek yapıların tamamı betonarme kullanılarak inşaa edilmişlerdir. Bu çalışmada yüksek yapılar, kullanılan malzeme türüne göre sınıflandırıldıktan ve özellikle yüksek dayanımlı beton hakkında bilgi verildikten sonra hesaplarda göz önünde bulundurulacak yük ler belirtilmiştir. Dördüncü bölümde yatay rijitük temini için kullanılan taşıyıcı sistemler, tüp sistemler ağırlık lı olmak üzere tanıülmışür. Beşinci bölümde yaklaşık hesap metodlan ve ön boyutlandırma teknikleri in celenmiş, Portal ve Cantilever metodlan birer örnek üzerinde gösterilmiştir. Altıncı bölümde içice tüp taşıyıcı sistemli bir yapının dinamik hesabı, oldukça etkili bir statik ve dinamik hesap programı olan SAP 90 üe yapılmıştır. Sonuçlar yedinci bölümde incelenmiştir.
Industrial urbanization created high-density living in urban spaces in city centers. These spaces were most often intermixed with each other in such a way that neighborhood stores, offices, and apartments were all inthe same building at different levels. The ground level was mostly stores and commercial functions and the upper levels were mixed-use with offices and residential functions. The nineteenth century urban centers in Europe, such as London, Paris, Prague, and Vienna, were very much of this kind of development. Industrial development during the late nineteenth and early twentieth centuries, combined with land speculation, forced a new kind of urban settlement pattern in which the living and working spaces became more and more separated in urban areas. The rise of downtowns and city centers consisting of office buildings and other commercial facilities created separate residential areas outside these urban centers. And even when some special residential centers were built near the urban centers, they were distinctly separate buildings in no way connected with the commercial or office building complexes. The architectural/engineering solutions for such specialized buildings were therefore quite different from each other. Theoffice and commercial buildings used larger- span structural systems consistent with the space requirements for offices and other commercial functions;whereas the housing and apartment buildings used relatively smaller- span structural systems consistent with residential room sizes. Although both reinforced concrete and structural steel were used for office buildings as well as residential buildings, the structural systems were quite different The office building, requiring longer spans as well as much more complicated mechanical and electrical systems, almost invaribly used false ceilings whereas the residential buildings, with less complicated mechanical and electrical systems, did not require the use of false ceilings except for special cases. Flat-plate, reinforced concrete slab construction therefore became the most accepted floor systems for residential buildings;whereas beams, joists, or grid beam (waffle) systems were used more frequently for office and commercial floors. Masonry bearing-wall construction almost always was used only for residential buildings of medium height As explained above high-rise buildings may be of various types and functions and they may have to respond to different demands. They may be also of various heights. Therefore there arise several problems to make decision on much as material to be used, structural system to be selected even to be developed. A high-rise building may be a single-use one or a multi-use one. For multi-use building it is necessary to develop structural systems that respond effectively to the needs of the different functions. In developing such systems, the first step is to select and appropriate structural material. The selection process must start with the most commonly used structural materials (steel orreinforced concrete, both normal and lightweight:composite systems and so forth). Although local relative economies must be considered, the selection process is much more difficult than is for a single-use building. The different requirements of the different functions and their relative importance in the overall project will be most important considerations. Some criteria and consideration are valid for multi-use as well as single-use high- rise buildings. In searching for appropriate structural systems one must recognize a number of important factors affecting the multi-use high-rise structure: - Interior column spacing-each use has a different optimum spacing. - Exterior column spacing-as a function of the planning module. - Spandrel beamshape and size-office and apartment "buildings 'have different requirements. - Floor to floor height-generally different for different functions. - Type of ceiling-traditionally the most economical and practical apartment ceiling is the xposed underside of concrete slab, while a hung ceiling is used in office and commercial buildings to provide access to HVAC and electrical system. - Transfer levels and transfer systems. - Floor plans-stepbacks, nonsymmetricsl conditions, and site considerations. VE Innovations leading to more economical and efficient buildings are only possible through a comprehensive understanding of the nature and behavior of various structural systems, and awareness of the relationship of the structure with other disciplines such as the mechanical system, and a practical sense of construction problems. A multi-use building is much more complex architecturally because of the different requirements for each use. For example, the maximum building with required for apartment space is generally much less than that required for an efficient office space; and the optimum column spacings for a residential building, as well as its plan flexibility, are distinctly different from those for commercial or office buildings. For high-rise buildings lateral loads are very important. Most common types of lateral loadings are Wind loading, Earthquake loading, Blast loading. In design these loadings are to be taken into account. Performance of the building must be satisfactory for which two criteria must be satisfied. Strenght and stability, serviceability Strenght and stability need not to be explained. On the other hand serviceability covers the problems of lateral deflections, relative vertical deflections, perception of lateral sway. For earthquake resistance and from the point of energy absorbtion a structural system needs to be ductile. In high-rise buildings lateral loads are very important and it is necessary to provide lateral resistance. Lateral load resisting units are Frames, shear walls, tubes. and from any or combinations of them several structural systems are derived among which the following can be cited: Frame buildings Shear wall buildings Staggered wall-beam systems vm Shear wall-frame systems Single framed tube systems Modüler tube systems Indesigning for earthquake loading generally there are several approaches. These can be classified int to main cathegories: The quasi-static approach Dynamic analysis In high-rise buildings joints are also of importance. One of the structural syst&ms is noteworth namely a closely spaced exterior frame system, referred to as the framed tube system, is being used increasingly for high-rise structures because of its inherent advantages in resisting lateral loads. In the case of multi-use buildings, where parking spaces within the building are frequent requirement, shear walls at the core create unacceptable inference and inefficiency. Framed tubes do not depend on shear walls or other trusses, and they can be used as a single tube form or arranged bundled form to respond to a special site configuration or larger floor area requirements. Framed tubes should be looked at as thin-walled hollow tubes with punched out holes (windows). Therefore the spacing and size of window openings is arbitrary and should indeed respond directly to be most desirable floor layouts. When a number of framed tubes are bundled together to form a bundled tube structure, the common walls of any two joined tube become an interior frame. The spacing of these interior tube columns has to be similar to that of the exterior. So that the spandrel beam at any one level is continous and has the same shear and flexural stiffness as for the perimeter elements. However, the exact dimensions and locations of these interior tube columns need to be coordinated with the planning layout of the type of occupancy. Quite often, the architectural design dictates large spacing of perimeter columns and shallow spandrel beams. A framed tube system consisting of shallow spandrel beams with large spans will be subject to large deflections and large interstory drift that are well beyond code recommendations. This type of framed tube requires considerable stiffening to reduce "shear lag". One of the methods of accomplishing this stiffening is an innovative approach that employs the precast facade as a stress-skin panel. In other words, the principal mode of resisteance in the precast facade panel is shear. Expansion joints are not desirable in symmetrically shaped buildings that are rectangular, circular, or square in plan, except in cases where the excessive dimension could not be tolerated by the extra onstruction necessary to overcome the situation. rx In the case of buildings with nonsymmetrical shapes like L T or U shapes, and with parts having different heights, properly located and designed expansion joints may significiantly affect or even control the behavior of the structure during earthquake motions. Aproximate analytical methods are available for almost all the identifiable regular forms of high-rise structure. More powerful and sophisticated computer programs for general structural analysis are now widely available, as well as some comprehensive programs for tall building analysis. Consequently the designer is usually able to analyze the most complex high-rise structure without recourse to the researcher. In this study, in the first three chapter high-rise buildings and the vertical and lateral loads have been categorized. In the fourth chapter, structural systems especially, tubular systems have been analyzed. In the fifth chapter preliminary or hand calculation methods have been analyzed. Portal and Cantilever methods asa the most popular techniques have been disscussed and an example problem have been solved. In the sixth chapter, a tube- in-tube system have been analyzed with SAP 90 structural analysis programme. In the seven chapter the results are discussed.
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1993
Anahtar kelimeler
Betonarme, Taşıyıcı sistemler, Yüksek yapılar, Reinforced concrete, Supporting systems, High structures