Anchorage Apartment Project Wins ICRI Award

Staff | September 28, 2010

Anchorage— The International Concrete Repair Institute presented one of its seven 2006 Awards of Excellence to an Alaska project.

The ICRI award in the Strengthening Category went to the seismic retrofit of McKinley Tower apartment building in Anchorage. This historic landmark is a 14-story reinforced concrete structure constructed in 1951–52 that was significantly damaged in the March 1964, 9.2-magnitude "Good Friday" Earthquake. Conventional retrofit measures began in the early 1980s but were later suspended due to the high costs involved, leaving the building vacant for approximately 20 years.

For this project, an innovative fiber-reinforced polymer retrofit design was implemented based on the seismic demands of the partially retrofitted building. The FRP retrofit design allowed for the elimination of interior shear walls, maximizing interior space use.

The FRP retrofit involved wrapping all columns to increase their compressive strength and ductility, transforming conventional bearing walls into shear walls, and shear reinforcement of coupling beams and boundary element generation in existing shear walls. It also involved shear and flexural reinforcement of cantilever beams and flexural reinforcement of roof slab for heavy equipment installation.

A total of 55,000 square feet of FRP fabric was installed in 11 weeks, allowing for a quick reopening of the historic landmark.

The project team included the owner, Marlow Development of Anchorage; the project engineer/designer, Schneider & Associates Structural Engineers Inc. of Anchorage; and the repair contractor, QuakeWrap Inc. of Tucson, Ariz., which also served as material supplier/manufacturer.