Optimal Topologies for Steel Frames with Ordinary Chevron and X-Braces: The Effect on Total Structural Cost

Today, steel structures with simple frames and concentric steel bracings (both crossed and chevron type) are extensively used in different countries, as well as in Iran. Apart from the seismic performance of each structural system, construction cost plays a significant role in system selection by designers. In an attempt to optimize structural costs, this study aims at examining the number of floors, span length, soil conditions, and brace type. In this study the impact of these factors on structural costs are evaluated. Since parking areas are the most important architectural requirement, therefore specified span widths accommodating two, three, and four vehicles are selected for the models. To this end, regular building models with different span (5.6, 7.5, and 11.2m) are selected according to such architectural considerations. Following structural analysis and design, total structural costs are estimated according to the latest national cost list issued by the Management and Planning Organization of Iran (published in 2014). The results are obtained and reported for different models through graphs and tables. The outcomes are evaluated and compared. Finally, the optimal topologies in terms of structure weight and total cost are determined, along with introducing the most effective factor among span length, story number, brace type, and soil type.