Vertical Load Carrying System | Post-tensioned concrete flat slabs supported by concrete columns and core shear walls. |
Lateral Force Resisting System | Concrete core shear walls with supplemental tall outrigger columns of steel reinforced concrete in the transverse direction. The core is attached to outrigger columns by steel buckling restrained braces. Water tanks at the top of the building are part of the "tuned liquid-mass damper" system to reduce wind induced motions. |
Foundation Type | Concrete mat foundation (12 feet beneath the tower) bearing on bedrock. |
Remarks | This building was instrumented jointly by the California Geological Survey and the U.S. Geological Survey. The building structural design was based on performance-based seismic design. |