OPTIMUM SHAPE OF OUTRIGGER SYSTEM FOR HIGH-RISE REINFORCED CONCRETE BUILDINGS UNDER EARTHQUAKE LOADINGS

Abstract

—Tall building development has been rapidly increasing worldwide introducing new challenges that need to be
met through engineering judgment. In modern tall buildings, lateral loads induced by wind or earthquake are often
resisted by a system of coupled shear walls. But when the building increases in height, the stiffness of the structure
becomes more important and introduction of outrigger beams between the shear walls and external columns is often used
to provide sufficient lateral stiffness to the structure. This study aims to identify the optimum outrigger belt truss shape in
tall buildings under earthquake loads. A 70 (triple belt ) storey , 50 (double belt) storey and 35 (single belt) storey
building was investigated with three different shape (warren , X & N) of outrigger belt truss , and optimum location for
single , double and triple belt take according to Bangle s. taranath , and from comparative study of without and with
variation of shape of belt truss with parameters displacement and storey drift under earthquake loading , and get a
optimum shape of outrigger belt truss for single(35 storey) , double(50 storey) and triple(70 storey).