1951 Harbor Bay Parkway, a new building (Figure 1) located in Alameda, CA, was developed privately for use as commercial office space by a life-sciences company. The project provided the opportunity to utilize an innovative approach for seismic bracing that provides improved performance and cost-effectiveness over conventional braced-frame systems. The system uses concentric buckling-restrained braces (BRBs) in conjunction with a vertical mast or strong-back to reduce drift, eliminate weak stories, and increase redundancy. The yielding BRBs work in tandem with an elastic mast frame to create controlled rocking behavior that provides more resiliency and improved protection for the building frame, cladding, and interior construction.

An Improved Approach for Seismic Bracing

In recent years, engineers have been seeking to capture the benefits provided by buckling restrained braces (BRBs) through the exploration of new braced-frame configurations to improve the seismic performance of building structures. One such alternative is the BRB mast-frame system, which enhances seismic performance and offers better architectural compatibility at a lower cost than conventional systems. The case study of 740 Heinz demonstrates the efficacy and cost efficiency of BRB mast-frames. …

An Innovative High Performance Structure

The San Francisco Public Utilities Commission’s (SFPUC) new headquarters in San Francisco, California, set a new standard for high-performance structures when it opened in June 2012. The building, slated for LEED Platinum certification, is a showcase for a host of leading-edge sustainable design elements, making it one of the greenest office buildings in the nation.

In this case, the design of the structural system, including its post-tensioned concrete shear walls and construction materials, made key contributions in achieving this distinction.

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