Implementation of Hybrid Mass Damper with Convertible Active and Passive Modes Using Multistage Rubber Bearing and Hydraulic Actuator for Vibration Control of Tall Buildings.

A hybrid mass damper using a hydraulic actuator and a multistage rubber bearing has been developed and implemented in the Long-Term Credit Bank of Japan Building which has a height of 130 m, a total floor area of 62821 m2, and a total weight of 39800 t. This mass damper can work mainly as an active one to effectively control relatively small vibrations of a building caused by winds and weak earthquakes. At the same time, it can work as a passive one against strong earthquakes. The moving mass has outer dimensions of 18×6.5×4.5H m and a weight of 195 t, and heat storage tanks are utilized as a part of the mass. The active-passive mode switching rules and a variable gain control law were adopted to make the mass damper perform more effectively against frequent winds and earthquakes. Excitation tests and simulations were carried out, showing that the mass damper continued to work in the active mode for strong winds and weak earthquakes, and that, for strong earthquakes, the passive mode appeared for a certain period of the excitation with large acceleration, and then the active mode resumed and effectively suppressed the residual vibration of the building.