Teknoloji Bağlamında Yüksek Binalara Yaklaşım

Abstract

Yüksek binalar nitelikleri gereği diğer bina tiplerine göre teknolojik gelişmelerle daha yakından ilgilidir. Strüktür malzemesi olarak çeliğin ve düşey sirkülasyonu sağlayan asansörün gelişmeleri ile 1880' lerde yapımına başlanan yüksek binalar, zaman içinde diğer teknolojik gelişmelerden de etkilenmiştir. Bu teknolojik gelişmeler ve bunların yüksek binalar üzerindeki etkileri, bu tezin ana konusunu oluşturmaktadır. Tez çalışmasının birinci bölümünde, çalışmanın amacı, kapsamı ve çalışma metodu hakkında bilgi verilmektedir. İkinci bölümde bu tezi oluşturan başlıca iki kavram olan yüksek bina ve teknoloji kavramlarının tanımları verilmiş, daha sonra yüksek binaları ortaya çıkaran nedenler ve yüksek binaların gelişimi konulan üzerinde durulmuştur. Çalışmanın üçüncü bölümünde, yüksek binaların tasarımlarını etkileyen teknolojik gelişmeler incelenmeye başlanmıştır. İlk olarak, yüksek binaların ortaya çıkışında önemli rolü olan düşey sirkülasyon teknolojisi bu bölümde ele alınmıştır. Dördüncü bölümde yüksek binalarda taşıyıcı sistem teknolojisi incelenmiştir. Burada öncelikle taşıyıcı sistemi oluşturan malzemeler konusunda bilgi verilmiş, daha sonra yüksek binalarda kullanılan taşıyıcı sistemler sınıflandırılmıştır. Beşinci bölümde ise yapım sistemleri teknolojisi ele alınmış, öncelikle yapım sistemleri genel olarak sınıflandırılıp, daha sonra çelik ve betonarme yüksek binalarda kullanılan yapım sistemleri hakkında bilgi verilmiştir. Tez çalışmasının altıncı bölümünde, bina kabuk sistemini oluşturan giydirme cepheler konusu ele alınmıştır. Yedinci bölümde yüksek binalarda oldukça önemli bir konu olan yangın güvenliği ele alınıp, bu konudaki teknolojik gelişmelere değinilmiştir. Yüksek binaları yakından ilgilendiren bu teknolojik gelişmelerle ilgili verilen bilgiler ışığında, Dünya' daki ve Türkiye' deki belli başlı yüksek bina örnekleri üzerinde yapılan irdelemeler, sekizinci bölümü oluşturmuştur. Sonuç bölümünde ise, yüksek bina tasarımında önemli rol oynayan teknolojik gelişmelere işaret edilmekte, Dünya' da ve Türkiye' de yüksek bina teknolojilerinde gelinen noktalara değinilmektedir.

Humankind has built refuges as they were created. Apart from the aim of sheltering, some symbolic-aimed buildings have been constructed as pyramid, tower and minaret throughout the history. They have came up today after getting into different stages. Today the building-site in cities decreased regarding to the increasing in population. For that reason, it is required to get the benefit of the limited numbered sites in maximum. At the end of 19th century, it was started to build high-rise buildings by the invention of elevator, the usage of steel in structure system and by the improvement of front(side) system. The construction of high-rise buildings in the U.S.A. has spread in a short period of time, but in Europe and in Turkey, this trende showed itself in 1950' s. People had lived in one or two storied buildings until the middle of 19th century, for 6000 years from the period of first city-like replacement, but they have started to live in higher buildings in recent decades. Today, cities have high rise buildings other than the lower ones. There are some reasons that reveal the high-rise buildings. a. The decreasing of the building sites in cities. b. The increasing in the building site prices. c. The need to replace the large building programme into the certain sites. d. The developing of the firms and the aim of prestige. e. Technological reasons The invention of cast iron in 18th century, the industry reform and the developing of steel production caused the using of steel-frames system and these systems has been used for the large end higher openings. Steel frames and glass surfaces replaced the heavy stacking walls. As the lift (which is a vertical transportation device) and the steel has improved, the high-rise buildings has been started to being built in Chicago and New York in 1880' s. "Home Insurance Building" which has ten-storeys and which had been built in Chicago in 1883-1886, was accepted as the first skyscraper by "Council on Tall Buildings and Urban habitat". The height and number of the tall buildings has increased in Turkey and all over the world by the technological improvements up today. Now, the highest building in the world is the "Sears Tower" in Chicago. The building which has 110 storeys as having a height of 443m. was completed in 1974, but Petronas Towers that is being built in Kuala Lumpur in Malesia will be 7m. Higher than Sears Tower and will be the highest building with the height of 450m. In our country the construction of higher buildings has started in 1950' s and today it continues. Now, the highest building in Turkey had been completed in 1991 and it is the "Mertim Building" having 50 storeys and 175.7m. height. The most important factor for the developing of these high rise buildings in Turkey and in the world, is the improvements in technology. The main technological developments which have a role in the improvement and designing of the tall buildings are vertical circulation, structure system, construction system, outer covering system and conflagration security system. The most important affect for the appearing of high rise buildings is the invention of elevator. The first passenger elevator has been used in Haughwout Store in New York in 1857. The device is an important development which is operating with steam and which arrives to the 5th storey in a period of time shorter than a minute. The speed of elevators, are used nowadys; the one in the Empire State Buiiding(102-storey) has a speed of (6.08m/sn), the one in the John Hancock Center in Chicago has the speed of (9.15m/sn). In Turkey the elevators having a speed 5m/sn. are in Sabaci Center, here the difference between the elevator technology can be seen easily. The planning of elevators is possible at the stage of the building planning as being different far each building. The elevator wells affects the architecture of building as it covers the whole building. When the tall buildings are researched, it is seen that, the sites occupied by the elevators, is equivalent to the %25-%30 of the storey sites. There has been some efforts to decrease this proportion and there has been an important improvement in the group-commanded elevators. Another important development in this subject is the invention of the two storied elevator cabinets. For example, "The Scotia Plaza" building in Toronto with 68 storeys. There are two cabinets in this kind of elevator which had been experienced as firdtly in 1932, so that at every stopping of the elevator, services were being done for both of the storeys. The usage of that technique became popüler and two storied elevators came into operation in the building of (Time Life) in Chicago in 1971. By using two-storied elevators, there had been 7200m2 disposal as %40. The role of the structure system is to transfer the load coming on itself in secure and to have the building standing. The structure system in high rise buildings carry the earthquake and wind burdens (whivh are called as horizontal load) together with the perpendicular burdens dependent to the number of storeys. The importance of the horizontal forces in the tall buildings increases as proportional to the height. They are all related. Generally structure system resists against the horizontal and perpendicular loads. We may classify the substances in three groups. They are reinforced concrete, steel and composite stuff. Also another affect in the appearance of higher buildings is the usage of steel in structure system. Home Insurance Building is the first one which was constructed by the carriage system in 1886. Today the highest building with the steel construction is "Sears Tower" with 443m. height. In the buildings of the tall buildings in the world, steel construction is mostly used, but in Turkey ther isn't any building which has been done by the steel construction. The reasons for this are the technic elements lacking of knowledge, workerswhish do not have experiences about steel constructions. Also the construction of steel buildings is more economic than the building of higher ones, so the usage of steel in building hasn't been required as the limit of 50 storey buildings. But today the project of higher buildings with the construction of steel, are prepared. It is estimated that these projects will be put into operation in the following years. Another substance that forms the structure system is reinforced concrete. The reinforced concrete in the structure system in tall buildings was used in "Ingalls Building" having 16 storeys in U.S.A. in 1903. Today technology has been applied to 80 storey. The highest building is the "311 South Wacker Drive "at the height of 289m. The important element that reflects the technology of concrete buildings is that in this building 840kg/cm2 concrete was used. Up to now, the most enduring concrete was used in the Two Union Square" building in Seattle in U.S.A. The resistance of the reinforced concrete which is used as first in the construction is 1330kg/cm2. The buildings which have been constructed in Turkey has 50 storeys at most, with the height of 175.7m. So that is "Mertim" was built in 1991. The concrete used in this building has the resistance of 400kg/cm2. When we look on the subject of cocrete technology. We may say that Turkey couldn't catch the standarts of the world technology. If we look at the application of structure system in tall buildings, we see that 110- 100 storeyed buildings have been constructed with the usage of tube system. In Turkey tube system has been used recently. The first operation of the tube system can be seen in "Mertim". Now, this is the highest building of Turkey. So, as it can be seen, tube system affects the height directly. Also it had a role in creating the places without coloumn within inner volume. When we look on the construction system of tall buildings, we are going to see that there was no need for the blocks in fittibg the steel, but the blocks were used only in the sections covewred with concrete. Some of the block system in the construction of concrete buildings are stucking-uproating blocks, climbing blocks, slipping blocks and tunnel blocks. Tunnel blocks are mostly used in the habitation building having 15-20 storeys. In our country mostly stucking-uprooting and climbing blocks. Slipping blocks are especially used in the legs of viaduct and in chimney towers. The reason of not using the slipping blocks is that the system is not known well by the technic staff. All around the world slipping blocks are used mostly because it is more economic and advantages. The first cladding system application in the world was realised in a two storied bank building in 1820, but the cast iron framed sides was put into application in New York at the end of the 1830' s. The Chrystal Palace which was built in London in 1851 is accepted as the essential of cladding system. Cladding systems has spread as the glass and metal technologies had developed after the 2. World War yher has been an increase in the building storey numbers with the development of these technologies. Because it is possible to build more storeys as the weight of XI the building decreases. Again here we see the importance of the technological developments in planning the tall buildings. The usage aluminium which was found in 1886, in architecture with the big scale occured at the store shop windows in Empire State Building in 1929. The aluminium in side was realised at the 7 storied Smith Corporation in Wiskonsin in 1930. The complete covering of a building with aluminium cladding system occured at the 12 storied business center in Oregon. After 1951, cladding system sides has spread rapidly. (World Trade Center, John Hancock Center.) after the 2. World War, the cladding system technology has improved as a result of the improvements in the fields of glass and metal. Esspecially reflective glass ha improved and it was started to cover the crooked surfaces. The cladding system with the reflective glass is used in the tall buildings in Turkey and all over the world. Another cladding system is the "precast reinforced concrete system" that is used in 15-20 storeyed buildings. One of the most important advantage of is that it may be produced as prefabric and also it is fitted easily. As the height of the building increases, conflogaration security becomes as the most important issue. When we search the examples in our country we see that importance is not given to that subject as required, it can be seen that the preventions relating to the fire security in the tall buildings are insufficient. The serious preventions about this matter are indicated in "The regulations of protection agains fire" which is prepared by Istanbul Büyükşehir Municipality in 1992. It is estimated that the fire security will be considered for the higher buildings that will be built in yhe follwing years by these regulations. So, we may file the conclusions that is taken clearly as these:. The development of the elevator technology had an important role in the increasing of the building heights.. The improvements in the reinforced concrete and steel technology (occuring structure system) caused the planning of high rise buildings and the increasing of them.. As the tube system has developed, the heighest building of the world has been built.. Clear and colonless residences can have been created by the tube system.. Structure system technology has been used for the device of architectural expression. There has been important developments in planning and front-mass geometry of buildings.. The projects which tend to the cim of architectural structure expression caused the improvements in civil engineering technology and methods. The static calculations of highj rise buildings has been done as more easier by the developments in the static calculation methods with the computer. So, it has taken short time and it brought that it is needed to make more projects and application. As the steel technology hasn' t improved in Turkey. The heights of buildings hasn' t reached the higher ones in the world.