Robert A. Young Federal Building

Featured on the cover of the January 2020 edition of Civil Engineering magazine, this 90 year-old, one million square foot concrete-framed structure covers a 3-acre site. Deemed vulnerable to seismic activity due to its location within 150 miles of two seismic zones (the Wabash Valley and New Madrid faults), its current occupants, the US General Services Administration, proposed a seismic renovation to provide its 3000 daily occupants with "both shelter in place opportunities during, and safe exiting from the building, following a seismic event."

Thornton Tomasetti provided the structural engineering analysis and design for this $75M project, and utilized a non-traditional solution for the strengthening of the existing lateral system. Rather than inserting concrete shear walls throughout the height of the existing structure, which would require significant disruption of the daily operations of the occupied building, the team utilized shear walls in the basement level only, and chevron frames incorporating fluid viscous seismic dampers with hydraulic pistons that move during a seismic event. The piston within the damper moves and compresses the fluid, counterbalancing the energy created when the floors would start to move.

More details of this project can be found online in the digital edition of Civil Engineering Magazine.