Influence of outrigger - belt truss on behavior of tall steel buildings with concrete core and circular plan

Abstract

Lateral displacement is one of the most important factors in the design of tall buildings. Different structural resistance systems proposed for resistance of gravity and lateral loads. One of the appropriate models in tall building design is structural model with concrete core that is the most important factor for structure’s lateral displacement and load control. With increasing the height of structures the influence of concrete core on lateral displacement control decrease in topper stories, because the concrete core stiffness decreases. To avoid this weakness, outrigger and belt truss is used with core concrete. In this article three steel structures with 30, 40 and 50 stories and 90, 120 and 150 m height and circular plan with 16 m radius was investigated, steel frame models with concrete core and belt truss-outrigger was modeled, analyzed linearly, designed and investigated. The results showed considerable decrease in structures drift angle with using belt truss and outrigger in steel structure with concrete core, without any important change in materials weight. In addition, structures stress ratio controlled and adjusted, and the number of plastic hinges and performance level was increased.

Keywords

• steel frame
• concrete core
• outrigger
• belt truss