Design methods of steel structures and these compares

Currently in modern structural engineering, there are two different design principle for the basis of structural steel design codes. First one is allowable stress method which was used as fundamental design principle in last century. Also during the last twenty years a new principle, limit state design method has been started to use by stages which is more rationalistic and based on probability theory. In our country Turkish steel code TS 648, which is used for design of the steel structure is based on allowable stress method. In addition, Europan Union Steel Design Code Eurocode 3 is used limit state design method.In this thesis, principles of the structural design and structural safety concept are explained. Also information about allowable stress method and limit state design was given. Turkish steel design code TS 648 and Europan Steel Design code Eurocode 3 were compared by their principle design concept and design rules. Section properties, section classifaction, tension, compression, shear force, buckling and others strength conditions which are defined in Eurocode 3 and TS 648, were detailed explained. Information about the braced steel frame was given. Two example project, 5 story office building and 7 story office building was analysed and designed both TS 648 and Eurocode 3 codes. Their differences, practicality, advantages to each other was investigated. As a result of the structural design, the weight of the structural steel elements was calculated for both codes and their economic effectiveness was compared. All rules, which were given by this study, were detailed exemplified in the example office building. Also information about historical development, application of national codes and sub-parts of the Eurocode 3 was given.Earthquake Forces was calculated by according to Equivalent Seismic Load Method given in Turkish Earthquake Restraint Code March 2007. Structural elements were designed by calculated internal forces obtained by structural analysis. For local site class, maximum effective story drift and the other seismic factors the rules defined in Turkish Earthquake Restraint Code March 2007 were used.