Importance of interstory velocity on optimal along-height allocation of viscous oil dampers in super high-rise buildings

The effective way of allocation of viscous oil dampers (capacity or size) is believed to place dampers to the stories which exhibit large interstory drifts. It is shown here that, while this understanding is almost true in rather low or medium-rise buildings, the distribution of the maximum interstory velocities plays a critical role in super high-rise buildings. It is further demonstrated that a large distribution of the maximum interstory velocities can be observed in lower stories in super high-rise buildings and this leads to a large demand of the maximum damping force in lower stories. It is concluded that the demand of relief forces of oil dampers is expressed in terms of (a) the maximum story shear forces of a frame without oil dampers which can be evaluated by the response spectrum method or other conventional methods, (b) the damper damping ratio, (c) the damping correction factor and (d) the higher-mode correction factor.