Young Seismic Retrofit Required Delicate Work, Pinpoint Scheduling
McCarthy Building Companies, Inc. has completed an innovative seismic renovation of the Robert A. Young Federal Building—one of downtown St. Louis’ largest office buildings—to improve the historic structure’s seismic performance.
The U.S. General Services Administration (GSA), which owns and manages the 20-story, 1-million-sq.-ft. building, undertook the $75 million design-build project to provide additional shelter-in-place opportunities and safe exits for the building’s 3,000 occupants in the event of an earthquake. Originally constructed in the early 1930s, the Art Deco brick and terracotta building faces potential seismic hazards because of its location within the New Madrid fault zone.
The project represented the first use of seismic dampers in a St. Louis building retrofit and the GSA’s first time using this alternative approach compared to more traditional seismic renovation methods. This novel strategy eliminated the need for 90 percent of the concrete shear walls traditionally required, streamlining the project schedule.
The design-build team’s innovative solution combined viscous dampers, steel braces and steel sheer walls, enabling all work to be completed while the building was 100 percent occupied by employees from 48 separate government agencies. Additional project elements included seismic bracing of non-structural components such as ceilings; partitions; and mechanical, electrical, plumbing and fire protection systems.
“Our McCarthy team worked closely with the designers and trade partners to identify and implement the most flexible, efficient design alternatives and to ensure that all construction work was well-coordinated with office moves,” said McCarthy Vice President Ryan Molen.
To complete the project on time and with minimal disruption to government organizations and their employees, construction progressed 21 hours a day—from 6 a.m. to 3 a.m.—with much of the work completed from 6 p.m. to 3 a.m. McCarthy scheduled and managed customized moves for each tenant. These included either relocating entire offices or temporarily consolidating office work spaces into more compressed areas. After four to six weeks, employees returned to offices that looked exactly like the space they left—from the original location of electric outlets to the exact positioning of each desk.
During the project, water and electric service for tenants was never disrupted, and all work was completed with close attention to environmental considerations, including controlling negative air flow, avoiding potential contamination, noise reduction, odor management and other best practices.
In recognition of the team’s overall commitment to safety, the AGC of Missouri recognized McCarthy with a Construction Project Safety Award for completing the project without a recordable incident.
The McCarthy-led design-build team includes Gensler (lead designer and architect of record), Etegra (associate architect) and Thornton Tomasetti (structural engineer). Other project team members included William Tao & Associates, Integrated Facility Services, Aschinger Electric and Wilson’s Structural Steel.