2005 ACEC OKLAHOMA

Engineering Excellence

"Grand Conceptor" Award

The 2005 ACEC OKLAHOMA Engineering Excellence “Grand Conceptor” Award winner is Wallace Engineering Structural Consultants for the Oklahoma History Center.  The $35 million, 190,000 square foot facility is located adjacent to the Oklahoma State Capitol.  It houses 40,000 square feet of exhibit space in five galleries, as well as offices, library and research areas, conference and event facilities, exhibit and artifact archives, preservation areas, and a gift shop.  The Center is home to the offices of the Oklahoma Historical Society and the State Historic Preservation Office.

The unique, curving geometry of the building was created in response to its site.  The three-story office/library wing is an S-shaped element and forms the entry side of the center.  The C-shaped gallery wings are nested into the office/library wing and face toward the State Capitol.  The two wings are joined by a three-story atrium spine and an elliptical-shaped Grand Hall.  The Grand Hall is a soaring atrium space that reaches 88 feet in height and is completely glazed on the exterior, providing a dynamic view of the State Capitol.

The exterior of the building consists of precast architectural concrete panels and glass curtainwall systems.  The precast panels are curved to follow the shape of the building and have marble tiles cast into them along the exterior colonnade facing the Capitol.  The Grand Hall is topped with a conical “headdress” with a skylight oculus at its apex.

The structural design of the Center incorporates creative uses of several common building systems.  One of the most unusual involves the use of precast concrete panels.  As originally conceived, the exterior skin of the facility was to consist of a combination of cast stone, marble, and backlit onyx.  The systems were to be used as veneers, which would require backup framing consisting of metal studs.  The gallery wings have a 30-foot floor-to-floor height, which would have required intermediate girts and wind columns to support the veneer framing.  Because of the deflection limitations required to prevent cracking of the stone, the framing would have been quite heavy, and the geometry of the framing, especially the studs, would be hard to control.

The design team started working with a precast manufacturer who makes high-quality architectural precast panels with a finish that resembles cast stone.  The use of the panels eliminated the need for backup framing in the cast stone areas.  The panels are also used as shear walls in conjunction with interior movement-resisting frames.  At the taller gallery areas, the design team decided to cast the marble tiles integrally with the precast panels to speed erection and reduce framing costs.

The floor plan geometry of the Center also created interesting and difficult framing challenges.  The structural grid system is laid out on a redial coordinate system, with the radial grids dimensioned angularly and the concentric grids dimensioned using distances.  The floor framing consists of composite steel framing and it was designed to create as simple a framing layout as possible.  The floor and roof framing are configured so that straight girders run along the concentric grids, creating a segmented curve.  Beams were placed perpendicular to the girders, so that all beam-to-girder connections were at 90 degrees.

The Center demonstrates that one can use standard materials in creative ways to attain a unique aesthetic.  The facility is unlike any in the area and demonstrates that thought and creativity must work in concert with engineering fundamentals. 

The Center was complex on many fronts.  The geometry of the building is the most visible complexity.  Also, exposed structural steel is used throughout the Center and is especially visible in the Grand Hall.  The steel tube framing not only had to meet architecturally-exposed steel requirements, but it had to be designed with simple elegant connections that would also brace the slender concrete columns supporting the roof of the Grand Hall.

Wallace Engineering provided full-service structural engineering design services for the project, and ACEC OKLAHOMA is proud to present the 2005 Engineering Excellence “Grand Conceptor” Award to Wallace Engineering Structural Consultants.