Different types of outrigger system in high-rise buildings: a preliminary comparative seismic analysis in a 40-story RC building

The rapidly growing number of high-rise structures around the world poses new obstacles, and lateral stiffness becomes one of the most critical issues as building height rises. The lateral stiffness and resistance capacity of high-rise buildings have a significant impact on structural efficiency, and structural engineers have introduced numerous capable constructions. The outrigger system is one of the most frequent and effective lateral loads resisting structural systems for improving structural stiffness and stabilizing the structure. The core shear wall provides structural strength in the main structural system, while the outrigger adds lateral stiffness. Several research on the outrigger system has been performed in previous studies, but a safe load transferring mechanism is the issue in the outrigger, as well as partial outrigger and belt depth, which has yet to be resolved. The concept of illumination and free space in outrigger structural systems is evaluated by comparing multiple outrigger system types utilizing a 40-story reinforced concrete building using ETABS 2017. The goal of this work is to do linear and dynamic (equivalent static and response spectrum) analyses, as well as nonlinear dynamic (time history) analyses of conventional outrigger, conventional outrigger with belt depth, virtual offset outrigger belt depth, conventional and virtual outrigger with partial depth under seismic load to better understand the performance and load transferring mechanism of distributed belt and conventional outrigger.