Capacity Interation Between The Steel Bracing and Concrete Frame

Steel bracing of RC frames has received some attention in recent years both as a retrofitting measure to increase the shear capacity of the existing RC building and as a shear resisting element in the seismic design of new buildings. An important consideration in the design of steel-braced RC frame is the level of interaction between the strength capacities of the RC frame and the bracing system. This interaction is caused as a result of the modifying effects of brace-frame connections and the manner in which the two systems share the applied load. The interaction manifest itself in the notion that the strength capacity of the brace-frame system found to be different to that obtained from the direct summation of the strength capacity of the brace and the frame, calculated separately. In this paper, results of experimental investigations aimed at evaluating the level of interactions between bracing system and RC frame are discussed. Based on these results the modifying effects of connections on the level of interaction between the two system capacities are evaluated. The results of this investigation would enable the design engineers to conduct a more accurate and economical design of brace-frame system.

Keywords:

Reinforced concrete , Braced RC frames , cyclic load tests Retrofiniting