Seismic Assessment and Retrofit of Pre-Northridge High Rise Steel Moment Resisting Frame Buildings with Bilinear Oil Dampers

This paper presents quantitative information on the effectiveness of seismic retrofit solutions using bilinear oil dampers for seismically deficient existing tall steel buildings. For this purpose, a benchmark 40-story space moment-resisting frame building is studied that represents 1970s design practice in North America. Rigorous performance assessment based ASCE 41 recommendations reveals high collapse risk building. The local engineering demand parameters are comprehensively assessed to quantify impact columns and column splices, which particularly vulnerable due time construction. Multiple schemes explored with numerous damping levels vertical distribution methods. designed via recently developed multi-degree-of-freedom curves method. A new balanced method proposed account effects inelasticity. strongly depends supplemental level, it determines employed results indicate strategies can minimize It shown provides most uniform drift along height. Despite reduction story ratios, axial force exterior remains relatively bottom stories regardless solution. On other hand, produce relative constant forces despite exhibiting higher velocity demands than expected.