A performance-based design approach for retrofitting regular building frames with steel braces against sudden column loss

作者：Tsai Meng Hao^*

来源：Journal of Constructional Steel Research, 2012, 77: 1-11.

DOI：10.1016/j.jcsr.2012.04.008

• Progressive collapse
• Performance-based retrofit design
• Column loss
• Steel brace
• Pseudo-static response

Progressive collapse resistance of existing building structures against sudden column loss may be increased with adequate supply of steel braces. A performance-based design approach for retrofitting regular building frames with steel braces is proposed in this study. The retrofit design approach is developed from the pseudostatic response analysis of an idealized elastic-plastic, single degree-of-freedom system. Analytical relationship between the increment of collapse resistance and structural characteristics is derived to determine the design strength and stiffness of added braces. Accuracy of the proposed approach is verified with incremental dynamic analysis. Also, its application to multi-story buildings is demonstrated with three frame models. Conservative performance is obtained with the design approach, especially for a larger resistance increment. An iterative modification technique is suggested to refine the retrofit design and only a few nonlinear static iterations are required for convergence. Nonlinear dynamic analysis results indicate that the column-loss response of the braced frames is approximated to the performance target and thus the proposed retrofit design approach is feasible for practical applications.

• 出版日期2012-10