The sixteen-story, 146,000 SF City Hall building was experiencing flexibility and significant lateral displacements during strong winds. A study of the structural system was requested by BJG Architecture and was performed by engineering firm, Miyamoto, and they found that the nearly 60-year-old building lacked seismic resiliency. Martin-Harris is currently performing these upgrades.

Miyamoto’s design for the seismic retrofit will add fluid viscous dampers to the existing structure’s steel moment resisting frames from floors seven to sixteen at strategic locations to decrease floor-to-floor deflections and acceleration during seismic events. Dampers will also mitigate movement from wind loading.

This work requires asbestos abatement of existing fireproofing to gain access to the column or beam elements. The damper work requires relocation of portions of the perimeter induction heating/cooling radiators to accommodate the size of the damper/strut assemblies. New plaster and spray fireproofing will be applied to the columns and beam elements after the structural work. Various metal-stud walls will be removed and rebuilt to accept the strut assembly.