Capitol Square Office Building and Parking Structure Renovation
Sacramento, CA
In downtown areas it is fairly commonplace to demolish existing buildings to make room for new high rise towers. In the case of the Capitol Square office building, rather than demolish an existing parking structure at the site, it was notched and a new 24-story tower was built adjacent to it. New shotcrete walls were added to stabilize the parking structure at the seismic separation between it and the new high-rise moment frame tower. To minimize beam depth and maximize openness at the perimeter, the tower frames were located one bay in from the perimeter essentially creating a rectangular “core” frame. Due to the variable depths of the gravel bearing strata that is used to support high rises in downtown Sacramento, ductile ties in the pile foundation system accommodate up to ten feet of cut-off. Power and data for the open office areas run through a metal electrified cellular deck with concrete topping to allow for maximum flexibility without the use of an access floor system.
Quick Facts
- Size: 550,000 SF office tower; 300,000 SF parking garage
- Architect: Dreyfuss + Blackford Architecture
- The largest column flange splice had 132 passes using 100 pounds of wire and took 6 hours to accomplish
- A wind study demonstrated resulted in a 1,328 kip base shear which was equivalent to the seismic base shear for the building
- Construction Cost: $60,000,000
- Contractor: Hensel Phelps
- Outdoor patios are located at the 22nd floor with a helicopter pad above the 24th floor
- The project utilized approximately 5,700 tons of structural steel
Photo credit: Chip Allen Architectural Photography