THE GEORGIA TECH HINMAN BUILDING RENOVATION

Built in 1939, the historic Hinman Building was the first freestanding research facility on the Georgia Tech Campus. 2010 saw the completion of a major restoration and adaptive reuse project which transformed the building into a design studio for the Georgia Tech College of Architecture.

Sustaining Gravity and Lateral Loads:

The unconventional decision to suspend the new floor “tray” from the existing crane was actually a practical way to resist gravity loading. In fact, the crane girders had adequate strength to support the lightweight steel tray structure, minimizing the need for additional columns and foundations which would have compromised the space below.

Lateral loads are resisted by attachment of the tray to the adjacent building floor structure at one end, and by utilizing a diagonal stair stringer at the other end. The use of the stair as a lateral stability element avoided the need for other obtrusive bracing within the space.

Aesthetic and Visual Impact:

Careful consideration was given to every detail of the exposed structural steel tray structure. Beams were tapered to minimize their appearance and express the nature of their internal stresses, thus serving as a learning tool for students using the space. Steel mesh was used in a catenary fashion to efficiently serve as a guardrail at the edge of the tray and at stairs.

All efforts were directed toward the creation of an elegant structure which expresses the nature of its steel construction.

Vibration Control:

Vibration control was a primary focus of the structural design. Because the tray has no suspended ceiling or superimposed partitions, it is very lightly damped. In addition the tray hangers are supported by outriggers which cantilever beyond the two crane girders, resulting in torsional vibration modes which needed to be considered. To address these concerns, Uzun & Case undertook a 3-D response spectrum analysis of the structure. This computer model enabled accurate prediction and limitation of peak structural accelerations.

Conclusion:

Utilizing structural steel, the project team was able to efficiently create additional floor space within the Hinman Building in a way that enhances rather than detracts from its historic character and aesthetic appeal. In the process, we were able to advance the art of steel design through the use of sophisticated computer models to design, document and control vibrations of the structure.

Technicalities aside, hanging a new floor structure from an existing crane was a pretty cool thing to do!