Permanent Damages of Structural Components in Existing High-Rise Steel Buildings Subjected to Rare Earthquakes

Severe ground motions generate permanent damages and residual deformations on various existing high-rise steel buildings, due to the effects of local-failure in steel and CFT members on the seismic damages have not been accounted in the provisions of current performance-based seismic design. In this study, component deterioration after local buckling of steel beam and columns is incorporated in dynamic analysis of existing high-rise steel moment frames subjected to long period ground motions. Performance-based earthquake damages are numerically investigated and compared in terms of the extent and distribution of plastic deformation ratios in beam and column components. Analytical results indicate that the characteristics of synthetic long period ground motions excited significantly different plastic deformations over the height of building structures. The component deterioration is not influential to the maximum responses of plastic deformation under the original scale of seismic excitations. The plastic deformation ratio of beams initiate and grow from the mid- floors, and the exterior connections sustained excessive damages.