Seismic design of a tall building with energy dissipation damper for the attenuation of torsional vibration

This paper reports a structural design method of a 100 m tall building using passive energy dissipation dampers, which made the unique architectural form of the building structurally feasible. This tall building will have 21 floors above ground and three basement floors, and will be an educational facility in the city of Osaka. The shape of the building is a unique combination of a rectangular parallelepiped and a quadrangular pyramid with a spacious atrium and a spherical hall inside. The main structure is composed of rigid steel frames, and the outer ones are equipped with dampers. The passive energy dissipation dampers applied to this project are mild steel plates with honeycomb‒shaped openings and capable of large elasto‒plastic deformation. They are expected to perform good energy absorption during earthquakes. As they are installed between vertical spans inside columns, they are consistent with the architectural planning. A structural problem caused by torsional vibrations in the event of an earthquake would be serious if the complex form of the building had not been considered. One of the major objectives of implementing such dampers is the stiffness and strength enhancement that adjusts and reduces the torsional vibrations to the normal level commonly encountered in a standard tall building design process. Time‒history analysis is carried out using a dynamic model to examine the structural performance of the building, which proves that the building is kept intact even under a large earthquake whose peak velocity is 50 cm s−1. © 1998 John Wiley & Sons, Ltd.