This paper describes the control characteristics of the Active Variable System (AVS) system applied to a high-rise building. The AVS system controls the structural stiffness to establish non-resonant states against large earthquakes. In practical viewpoints, 10% damping factor produced by variable stiffness devices is introduced to three selectable stiffness types. The non-resonant control gives smallest responses in uncontrolled three stiffness types, thus producing significant response reduction especially for earthquakes with narrow-range long-period component. The control also reduces input energy of earthquakes, so it realizes effective control with small amount of energy absorption of the variable stiffness devices.
