Study of Effect of Aspect Ratio with Uniform Plinth Area on Seismic Behaviour of R.C. Structures Using Outrigger System With and Without Belt Truss - A Literature Review

The rapid developments of materials, construction technologies and structural systems have given rise to a significant increase of skyscrapers over the past decades. The reduction of the top drifts and base core overturning moments under lateral loads, such as earthquakes and wind loads, has drawn increasing attention in the structural design of super-tall buildings. When building height increases, the structure should have a lateral load resisting systems other than shear walls for avoiding the effect of these loads, since the shear walls when used alone are suitable only up to 20 stories high. Outrigger systems are one such prominent system and are considered to be the most popular and efficient because they are easier to build and provide good lateral stiffness. The principle of using an outrigger system to enhance the structural lateral stiffness and overall stability is that the core-tube and the external columns are connected by rigid horizontal cantilevers. Optimum locations for Installations of outrigger systems with and without belt truss system can be founded. A relatively new concept of Virtual Outrigger is introduced in this paper. In which, using only the belt truss in the building in order to increase the performance of the building under the dynamic loads is studied. Emphasis is given to the various benefits of employing Virtual Outriggers instead of Conventional ones. Overall displacements and lateral drift can be reduced. Outrigger systems enhance the stiffness of high-rise buildings by the introduction of stiff outriggers and belt truss at different locations. The loads considered are as per IS codes. An ETABS model of 30-storey building is considered for this study.