115. Case Study on San Diego Courthouse by Structure Magazine
The new San Diego Central Courthouse is a bold and iconic civic landmark that replaces the seismically vulnerable existing courthouse facility.
114. Tempering Tremors: San Bernardino Courthouse
Application of Taylor Devices dampers in a steel frame structure building.
112. Seismic Upgrade of an Existing Tall Building by Different Energy Dissipation Devices
In this paper, three kinds of supplemental energy dissipation devices are investigated to upgrade the seismic performance of the case study building, including fluid viscous dampers, viscous wall dampers, and buckling restrained braces.
111. Seismic retrofit and FEMA P-58 risk assessment of mid-rise soft-story concrete towers
110. Braced for the Future: A MSC Case Study on 181 Freemont
109. The Winds of Time: a Case Study on 250 West 55th Street
This paper discusses model, design, and application of viscous dampers in one the skyscraper in New York City.
108. Seismic Retrofit of the Tower of Hope – Preservation of a Masterwork of Mid-Century Modernism
The two frame office towers, constructed in the 1970s per the 1967 edition of the UBC, use perimeter reinforced concrete moment frames to resist seismic loading. The buildings are rectangular in plan and have certain characteristics that adversely affect their seismic performance, in particular the presence of a soft-story response at the first floor (approximately 50% taller than typical floors), and limited ductility typical of buildings of that era. Risk analysis showed that for the towers the PML exceeded 20%. Nonlinear response history analysis (NLRHA) of the towers was conducted and showed that in the existing configuration, the story drift ratios (SDRs) at the first floor exceeded 2%, shear hinging of the first floor beams was expected and that the SDRs would need to be reduced to approximately 1.4% for the first floor to limit the extent of nonlinear response. Seismic retrofit included addition of 300-kip viscous dampers in both directions to the first floor of the building.
107. STEEL MOMENT FRAME WITH SUPPLEMENTAL FLUID VISCOUS DAMPERS – 12 MOORHOUSE AVENUE A CASE STUDY
This paper provides a case study of a five story commercial building, where supplemental fluid viscous dampers are combined with a steel moment frame structure to provide a dual seismic resisting system. The paper outlines the analysis and design procedure.
106. A Study in the Long-Term Performance of Specialized Low Friction Hermetically Sealed Fluid Viscous Dampers under Nearly Continuous Operation on a Pedestrian Bridge
This paper will outline the specifics in quantifying the continued damper performance through an intermediate inspection after seven years, followed by a successful comprehensive inspection after eleven years. This included the removal, dynamic testing, and re-installation of three selected dampers.
102. TORSIONAL CONTROL OF TWO ADJACENT OFFICE BUILDINGS USING VISCOUS DAMPERS
Two adjacent wings of a three story office building in Southern California were found by analysis to be excessively responsive in torsion under an earthquake on the near-by Newport-Inglewood fault, some five miles from the site. The generous 4.5″ seismic separation between the two office building segments was found to be inadequate to prevent heavy pounding even in a moderate event, having a high probability of occurrence at this location. A variety of structural retrofit schemes were evaluated to mitigate the excessive torsional responses of the two building segments. These included converting the perimeter gravity frames to moment resisting frames, adding diagonal bracing to the perimeter frames, tying the two structures together at each floor level, and using viscous dampers as attachments between the buildings. The best solution from a cost, schedule, construction disruption, and earthquake performance standpoint, turned out to be joining the two building segments with horizontally oriented viscous dampers at a single floor level. This paper describes the analysis and retrofit solution that was used, and discusses the advantages and disadvantages of the retrofit options studied.