The Seismic Investigation of Off-Diagonal Steel Braced RC Frames

Slovak Journal of Civil Engineering

Keyvan Ramin^1¹  Mahmoud R. Maheri^2² 

[1] Ferdowsi University of Mashhad, Mashhad^1;Shiraz University, Shiraz^2

关键词: ODBS;    Concentric steel brace;    Steel bracing;    RC frame;    Buckling;    Hysteresis capacity;    Time history analysis;   

DOI  :  10.2478/sjce-2018-0020

学科分类：建筑学

来源: Slovenska Technicka Univerzita v Bratislave * Stavebna Fakulta

【 摘 要 】

Steel bracing may be used to enhance the seismic strength of RC frames. Concentric steel bracing generally reduces ductility, which is a key component of seismic design. To overcome the problem, ductile steel brace-RC frame systems are therefore usually introduced in the form of eccentric braces. In the present study, the Off-Diagonal Bracing System (ODBS), which works as a concentric type of bracing, is investigated. In this paper the response of ODBS elements to cyclic loading is first explored and compared with those of other types of bracing such as X-bracing and inverted-V bracing systems. The time history analysis responses and cyclic hysteresis responses of a number of lowrise to mid-rise RC frames retrofitted with different types of bracing systems are then evaluated and compared. It is shown that under seismic excitation, a much reduced base shear is experienced by frames retrofitted with ODBS compared to other bracing systems. The results of time history and cyclic hysteresis response analyses also indicate a far greater energy dissipation capacity and ductility for the ODBS compared to other bracing systems. It is also concluded that ODBS performs best in lowrise frames. The out-of-plane buckling response of the ODBS is also investigated, and it is shown that a double-plated central connection can control such an adverse response.

【 授权许可】

Unknown