By questioning the status quo, we’ve developed improved approaches for the design of steel structures that provide better seismic performance with no cost premium. Through iterative design and decades of research and development, we reconceived the approach to seismic bracing to create a more resilient system. By introducing an elastic mast to an otherwise conventional braced frame, we’ve been able to improve the performance of steel structures and make them more damage resistant with minimal cost and architectural impact. 

At the Exelixis Life Sciences Headquarters, the team devised an innovative approach for seismic bracing that provides improved performance and cost-effectiveness over conventional braced-frame systems. A mast-frame system uses 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 improved resiliency and protection for the building frame, cladding, and interior construction. The mast-frame occupies the same footprint and extent of a conventional frame, but uses fewer BRB members. The mast effectively forces all of the BRB’s in the system to work together to resist movement at any story, which fully mobilizes the BRB elements’ deformation capacity and increases the system’s inherent redundancy.

At Tipping, we employ custom tools and advanced analytics to design structures that not only meet the minimum life-safety objectives prescribed in the building code, but also provide enhanced post-earthquake resilience that reduces potential harm, economic losses, and overall construction costs.  By harnessing the insight from our data-driven process, we pioneer innovative strategies for seismic protection that lead to unconventional approaches—our powerful suite of custom designed tools has allowed us to be at the forefront of major innovations in seismic design including BRB mast frames, post-tensioned walls, and seismic isolation.

The 680 Folsom team created a unique lateral system—unprecedented in modern engineering—that saved $4 million on a $110 million project and provided enhanced seismic performance. Inspired by Japanese pagodas, the design solution was founded on the shinbashira, or central pillar, of the centuries’ old Japanese pagoda. The team invented a modern shinbashira in the form of a concrete core-wall system resting on a single friction-pendulum slider bearing that pivots within its base. Harnessing the strength of the existing moment frame, the system acts as a mode-shaping spine that improves the drift pattern and spreads yielding throughout the frame’s height, thus redistributing seismic deformations throughout the structure and preventing the formation of a weak-story mechanism.