Analytical Investigation on the Effect of Connection Type of Steel X-Bracing to the Reinforced Concrete Frames

Document Type : Research Article

Authors

Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran

Abstract

Using steel braces is regarded as one of the significant methods for retrofitting and seismic rehabilitating of reinforced concrete frames. Thanks to its easy implementation, economic considerations and appropriate seismic retrofitting performance against lateral forces, this system has received more attention from researchers in comparison with other seismic resistant systems. In this type of structural system, the connection properties are of high significance and they can play a significant role on the obtained results including ductility, resistance, stiffness, etc. The detailed behavior and performance of this type of connection have received less attention from researcher; hence, it is regarded as an under-researched issue. In the present study, we addressed this research gap; we made an effort to comprehensively explore and investigate this issue. ABAQUS finite element software was applied for modeling and numerical analysis; a total of 8 models were analyzed and investigated which were categorized into 3 different groups with respect to the type of steel brace connection to the reinforced concrete frame. These connections include steel bolts and plates, steel jacket and steel box which were modeled and discussed under different conditions within each group. Nonlinear analysis of samples indicated that the connection of steel bracing to the concrete frame by penetrating bolts in concrete and steel plates led to significant enhancement of stiffness, resistance and ductility. Furthermore, these reinforcements have maximum energy dissipation, minimum concrete frame cracking and steel consumption reduction in joints.

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