Fire Station Number Five

Salas O’Brien faced the challenge of designing the new Frederick Firestone Fire Station #5 on an abandoned coal mine site from the early 1900s, requiring complex structural engineering. The site had a significant subsidence risk estimated to be 0.45 feet over the length of the building.
Following the state geological report’s recommendation, the station has as three separate buildings with complete isolation joints throughout the foundation and extending up through the roof structure. This design approach reduced subsidence to 0.23 feet, nearly half the
original estimate.

We designed the foundations as shallow raft foundations broken into three monolithic pieces that could float on the soil below while providing the necessary shear and bending capacity to resist the additional forces induced by a subsidence event. In lieu of traditional CMU, we designed the
interior containment perimeter and the exterior envelope of the apparatus bay with cold-formed steel (CFS) infill wall framing with CMU veneer. This allows the superstructure and wall framing to maintain their structural integrity and full operational performance after a subsidence event, requiring only cosmetic repairs to the damaged CMU veneer.