Application of seismic isolation techniques for slender tall steel building requires several attentions in structural design. One is the horizontal stiffness of superstructure to maintain seismic isolation effects, and another is the uplift effect of the isolation bearing with overturning moment caused by earthquakes. In this paper, a practical design of the tall seismic isolated steel building with high aspect ratio is reported. To satisfy the above conditions, single-span moment frame structure with mega-braces on both sides are introduced, and their efficiency is discussed.
