Historic Hinman Research Building transformed into a design studio
2010 saw transformation of the 1939 Hinman Research Building into a design studio for the Georgia Tech College of Architecture. Working collaboratively, architects Lord Aeck & Sargent /Office dA, structural engineer Uzun & Case, and contractor The Beck Group skillfully preserved and revitalized the original 35,000 square-foot building.
It made sense to add additional floor space within the high-bay space, but the design team was concerned about preserving its historic character and open feeling. These issues were artfully resolved by hanging a thin floor structure (tray) from the building's existing crane girders. The team Adapted the historic component of the building while eliminating columns down to the original building floor beneath was a win-win proposition. In fact, the crane girders had adequate strength to support the lightweight steel tray structure.
That being said, the scheme posed significant vibration control challenges. As a space for the GT College of Architecture, aesthetic considerations were paramount. 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. 5/8 diameter hanger rods express tension while making the structure seem to float in 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 was a primary focus of the structural design. The structure is very lightly damped and has cantilevered outriggers which result in torsional vibration modes. To address these concerns, Uzun & Case created a computer program to implement a 3D response spectrum analysis of the structure based upon walking excitation. Using the model, an efficient vibration control strategy was developed. ¾ in. diameter rods connecting the crane girders to the roof trusses above were utilized to control torsional behaviour. 1 in. diameter rod bracing between the tray and adjacent building columns controlled both lateral and vertical movements.
After completing construction, tray accelerations were measured by Uzun & Case, confirming compliance with open office acceptability criteria. The Hinman Building received LEED Gold certification from the U.S. Green Building Council. 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, the team 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.