SEISMIC RESPONSE OF REINFORCED CONCRETE CONCENTRICALLY A-BRACED FRAMES

Abstract

Braced frames widen their resistance to lateral forces by the bracing action of inclined members. The braces stimulate forces in the associated beams and columns so that all work as one like a truss with all members subjected to stresses that are for the most part axial. This axial reaction results in less moments and in turn smaller sizes of beams and column sections compared to moment resisting frames. A concentrically braced framehas minor eccentricities in the joints of the frame that are accounted for in the design (which is tried with A-braced or K-braced or concentrically braced frames for this work). This paper presents the elastic seismic response of reinforced concrete frames with reinforced concrete bracing member in K or A –braced pattern which are analyzed numerically for twelve storey building with 5-bay structures. This approach focuses on the arrangements of A-braces in a particular bay, level and combinations thereof to reduce the lateral displacement ultimately to achieve an economy in comparison with similar moment resisting frames. Results are concluded from graphs and discussed comprehensively.