Dual frame systems of buckling restrained braces

Abstract

The thesis aims at investigating the behavior of reinforced concrete frame structures retrofitted with dissipative buckling restrained brace systems. On this purpose, numerical investigations and experimental tests were conducted, in order to evaluate the effectiveness and the functionality of a buckling restrained brace system and its influence on a reinforced concrete portal frame. Modeling parameters for buckling restrained braces were determined. Acceptance criteria were proposed for this particular case, then a performance based seismic evaluation and design was applied on the case study. Finally, the seismic reduction factor (q) was evaluated by means of nonlinear analysis and compared to the experimental values. A methodology for the performance based evaluation and design was proposed. Numerical analysis performed on the retrofitted reinforced concrete frame has shown an improvement of the seismic performance. The final experimental results confirmed and validated the buckling restrained system functionality both at local level (BRB element and its connections with reinforced concrete elements) and at global level (RC frame behavior).