The effect of the number of bay and storey on the economy and seismic demands of the steel moment resisting frames

The principles of safety, economy, and aesthetics (3E) are taken as basis for the design of structures. Although the design of ductile moment resisting steel structure systems can be provided with the current regulations and engineering methods, the proposed designs may show great differences in terms of weight of the structural system. Although the design processes are directed by the zoning plans that are prevailing in the area where the structure will be built, in the thesis study a parametric study was carried out using plane frames having different storeys and spans. With the findings obtained within the scope of the thesis; it was determined that the most effective requirement in the design of ductile moment resisting frame systems is the requisition of using stronger columns in beam to column joints, which is followed by requirements about the cross-section slenderness and the relative storey drift, respectively. It is possible to say that the use of high strength materials in order to minimize the weight of the structural system in the design processes may have more negative effects than positive effects due to the limitation in the cross-section slenderness. For structural column members, using small cross-sections that are sufficient in terms of strength and strong column-weak beam requirements may result with a decrease of in the rigidity of nodal rotation that leads to decrease in the horizontal translation rigidity of the structural frame. The necessity of focusing on horizontal geometry as much as possible, the importance of choosing low strength materials, the advantages of focusing on spans not exceeding 5.0 m as much as possible and avoiding the use of HEA type sections in structural column members come to the fore in the design processes of ductile moment resisting frame systems.