Evolution of Outrigger Structural System: A State-of-the-Art Review

This paper presents the development of the outrigger structural system from the conventional outrigger to damped outrigger concepts. Outrigger structural system development from the conservative design as a rigid connection to a virtual connection with passive control, active control system, semi-active control system to hybrid control system is deliberated. Following brief overviews on history of outriggers, types of the outrigger, analysis of tall buildings without outriggers, formulation of equations for outrigger structure to simplify analysis are elaborated. Different approach to locate optimum positioning of outriggers in tall structure is elucidated. Analysis of outrigger to study its behavior in high-rise buildings using different methods is stated, and review on the damped outrigger system is explicated. This paper tries to highlight the advantages of outrigger structure with semi-active control and performance enhancement of the outrigger system with the effective devices, and enhanced results are also depicted. This review also paves a way for the new area of research in structural control with the incorporation of smart devices and smart technology.