Paper Title
Application Of Outrigger In Slender High Rise Buildings To Reduce Fundamental Time Period
Abstract
Worldwide there is a rapid increase in development of tall buildings especially in Asian countries there is an
increase of 318% in a decade. The structural engineers faced the new challenge with an engineering perspective and
suggested many solutions one such is coupled shear wall for restraining wind and earthquake induced lateral loads. But when
building is slender in any of the direction lateral stiffness of the structural system becomes more important and outrigger
system is introduced between the core wall and external columns to provide lateral stiffness. The outrigger will effectively
control the excessive drift and deflection in seismic active zone or wind load dominant area and minimize structural
damage. The objective of this study is to find the optimum location of the outrigger beams. For this purpose mathematical
model of 30, 40, 50 & 60 storey is created in FEM base Etabs software. Variation in the fundamental time period of building
without outrigger and different location of outrigger is examined. There is a maximum reduction in the fundamental time
period of the building is achieved by placing first outrigger at 1/3rd
storey height from top and second outrigger in same
height from bottom. Results shows that dimension of plan also has a role to play in stability .Increase in height with same
plan geometry lead to increase in fundamental time period thus can say lateral stability of the structure is inversely
proportional to the height of the structure.