Interactively economic design of multi-storey steel structures

There are two philosophies today which are bases for the designing of structures. The first one is allowable stress design method, and the second is limit states design method. Allowable stress design method has enjoyed a long history of usage. Limit states design method is commonly used in both reinforced concrete and steel structures recently.In the scope of this study, basic principles of design and structural safety concept are explained and general information about allowable stress design and limit states design methods, which are used in the specifications, is given. In the applications, members of 15-storey building consists of high level ductile steel frames are sized separately according to the Eurocode3, AISC-ASD and AISC-LRFD specifications under the vertical and earthquake loads. Sap2000 software is used in the designs. Thus, by changing the structural members interactively more economical designs (lighter structures) are investigated using the three specifications. Moreover, the designs of the three specifications are compared. Accordingly, the most economic solution is obtained using AISC-LRFD specification.