INFLUENCE OF BRACING SYSTEMS OVER THE FUNDAMENTAL FREQUENCIES & THE FUNDAMENTAL PERIODS OF R.C. STRUCTURES

When a structure is designed for seismic resistance various systems are embedded into the structure so as to resist the lateral forces. The most common systems which are used for retrofitting are structures with different types of bracings and shear walls. Inclusion of steel braces and the shear walls into the structure definitely influences the stiffness of the frame. The variation in stiffness will affect the fundamental frequency and the fundamental time period of the structure. According to IS 1893(2002), the fundamental time period is governed by the base dimensions and the height of the structure. In this paper the effect of different types of bracing system on the story stiffness, fundamental frequency and the fundamental time period have been studied.