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 significant subsidence risk estimated to be 0.45 feet over the length of the building. Following the state geological report recommendation, the station was designed as three separate buildings with complete isolation joints through the foundation and continuing up and through the roof structure.

This design reduced subsidence to 0.23 feet, nearly half the original value. 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. We designed the interior containment perimeter and the exterior envelope with cold-formed steel (CFS) infill wall framing with CMU veneer, which allows the superstructure and wall framing to maintain structural integrity and performance after a subsidence event, only requiring cosmetic repairs to the damaged CMU veneer.