We propose a method using high-strength steel stud columns for seismic retrofit of existing high-rise steel buildings to prevent excessive residual deformations. The essential requirement of the present method is that the post-yield story stiffness including the P-Δ effect be positive. The present method requires strengthening members much less than conventional retrofit methods. We demonstrate in numerical examples that the use of 800 to 1000MPa class high-strength steel allows the stud columns to be elastic even when interstory drift ratio is 0.02. It is also shown that the present method is effective to prevent the occurrence of excessive residual deformations under long-period ground motions caused by a subduction earthquake.
