Dramatic Cantilever

Dramatic Cantilever

Singh Center for Nanotechnology Wins National Architecture and Engineering Award


(Chicago, IL) – The Krishna P. Singh Center for Nanotechnology, a 78,000-sq.-ft research and teaching laboratory on the Philadelphia campus of the University of Pennsylvania, has earned national recognition in the 2014 Innovative Design in Engineering and Architecture with Structural Steel awards program (IDEAS2).
540a97c434edbc57d8b55fae50b468a8The center’s most dramatic and complex structural design feature is the forum, a 4,000-sq.-ft assembly space that cantilevers 68 ft over the courtyard and includes multi-purpose functions such as lectures, receptions and meetings. Strength and vibration were core design parameters, and the vibration of the floor under dynamic human loading is the controlling criteria of the structure. The vibration of the floor beams and the overall rhythmic vibration of the room are controlled by the stiffness of the steel trusses and lateral restraint of the braced frame. The cantilever is constructed of two inverted trusses with hang columns to capture the horizontal floor diaphragm.



The south-facing curtain wall façade of the center’s galleria has a sloping roof that slices through the curtain wall plane stepping it in two directions. A horizontal truss diaphragm is employed at the sloping roof plane to resist the horizontal wind loads on the curtain wall. The north side of the horizontal truss is supported by steel columns on the foundation wall. The south side of the horizontal truss is more structurally dynamic and is supported by cantilevered beams with hanging columns that suspend the north edge of the truss from above. The hangers and columns are all architecturally exposed structural steel (AESS). In order to match the construction tolerances of the AESS, slip connections are provided where the hangers meet the upper roof steel. The lower roof between the hangers and the columns is constructed with AESS tolerances.

The monumental stair is unusual because it is a 55-ft-long free-span stair stringer supported by a 24-in.-deep, 20-ft cantilever. Though deflection and strength were considerations, similar to the forum, vibration parameters controlled the design. Five 24-in.-deep steel wide-flange members frame the 10-ft wide stair.

The laboratories require very strict vibration tolerances for maximum equipment performance. The lower level transmission electron microscope (TEM) rooms require a completely isolated six-sided box construction. The clean room bay and chase have 52-ft free-span beams that create a column-free space for maximum flexibility, and the general labs contain 34-ft free-span beams to allow for a column-free space. This design resulted in an actual vibration criterion that exceeded the anticipated design criteria.

The building’s project team members include:

Owner: University of Pennsylvania, Philadelphia
Architect: WEISS/MANFREDI, New York (entered project in the competition)
Structural Engineer: Severud Associates, New York
General Contractor: Gilbane, Inc., Philadelphia
Steel Fabricator: Lynchburg Steel & Specialty Company, Monroe, Va. (AISC Member/AISC Certified Fabricator)
Steel Erector: Steel Suppliers Erectors, Inc., Wilmington, Del. (AISC Member/AISC Advanced Certified Steel Erector)
Steel Detailer: Delta Structural Steel Services, Idaho Falls, Idaho (AISC Member)UPENN, Singh Center for Nanotechnology


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