San Francisco Tower Earns Earthquake-Resiliency Certification

Down the street from the sinking Millennium Tower, another skyscraper earns a REDi Gold Rating and becomes the most earthquake-resilient structure on the west coast.

While the Millennium Tower continues to sink as legal battles ensue over who's at fault and should pay to stabilize the structure, another tower on the same block recently became an example of earthquake resiliency.
181 Fremont recently achieved a REDi Gold Rating, based on the Resilience-based Earthquake Design Initiative developed by Arup, a design and engineering consultancy. According to the design and planning guidelines, the rating concludes this new structure will be able to withstand a 475-year seismic event, or Magnitude-7.5 or Magnitude-8.0 earthquake.

A rendering of 181 Fremont, where the green space beside it is the intended location of a subway line, and the sliver of tall glass building on the left is the Millennium Tower.

"Given 181 Fremont's location in a seismic zone, building height and mixed-use nature, we felt strongly the expenditure of extra dollars to achieve a REDi™ Gold Rating resulted in a safer and higher quality product. 181 Fremont will offer class-A commercial space and the highest quality luxury condominiums on the market," Jake Albini, Senior Manager of Real Estate Development at Jay Paul Company, which developed 181 Fremont, said in a statement.
To achieve this standard, Jay Paul Company and Arup, which served as the structural and geo-technical engineer on the building, included viscous dampers within the steel mega-braces that will act as shock absorbers and uplifted mega-columns to significantly reduce the potential for earthquake damage. These solutions also reduced wind vibrations, which allowed the developer not to use a mass roof damper and freed up the entire penthouse floor for sell-able square footage.
The REDi Gold Rating was designed to reduce damage to the structure, improve egress systems in case of emergency, and create contingency plans to reduce recovery times. Arup is currently creating a similar rating system for flooding.

 http://www.builderonline.com/building/