tt building175The University of Iowa’s new Hancher Auditorium makes its debut on September 9. With a sculptural form composed of curving, cantilevered terraces clad in stainless steel and glass, the 1,800-seat performing arts facility is the result of intensive collaboration among design-team members from 17 organizations. Theater design is never simple, but a compressed schedule and atypical geometry added complexity to the design process. Thornton Tomasetti’s façade specialists, structural engineers and construction support professionals worked closely with one another and with all design and construction team members to develop sophisticated solutions to several significant engineering challenges.

The University of Iowa’s new Hancher Auditorium makes its debut on September 9. With a sculptural form composed of curving, cantilevered terraces clad in stainless steel and glass, the 1,800-seat performing arts facility is the result of intensive collaboration among design-team members from 17 organizations. Theater design is never simple, but a compressed schedule and atypical geometry added complexity to the design process. Thornton Tomasetti’s façade specialists, structural engineers and construction support professionals worked closely with one another and with all design and construction team members to develop sophisticated solutions to several significant engineering challenges.

Fig. 1 - The new auditorium building features dramatic cantilevered overhangs. The sculptural form required creative structural design (Thornton Tomasetti).Fig. 1 - The new auditorium building features dramatic cantilevered overhangs. The sculptural form required creative structural design (Thornton Tomasetti).

Fast-Track Schedule Required Early Steel Bid Packages

A requirement for early steel bid packages – for foundations and the superstructure – put structural design far in advance of other disciplines. Because no two theater designs are alike, our engineers reached out often to all team members for details on their design criteria, equipment choices and loading requirements. Insight gleaned from past theater projects taught us which questions needed to be asked. Establishing these particulars upfront increased the quality of our construction documents, reducing the potential for coordination issues later on.

A Three-in-One Solution for Vibration

To meet the strict acoustical and vibration requirements of a top-notch performing arts venue, the facility is actually three distinct structures wrapped in one façade. The auditorium at the heart of the facility consists of 24-inch-thick concrete walls that curve to maximize acoustic performance and also provide the structure’s lateral support. Lobby, circulation space and support areas, framed in steel, wrap around the auditorium and define the sweeping form of the building. This structure features dramatic overhangs, including a 70-foot, two-way cantilevered terrace. The third section is a three-and-a-half-story, steel-framed structure that houses rehearsal space. The central auditorium is separated from the other structures by a two-inch isolation joint and vibration isolation bearings, which keep noise from the surrounding areas out of the performance space.

Fig. 2 - This structural Revit model shows the large, steel-framed cantilevers of the southeast lobby. We worked closely with the architects to find patterns in the asymmetric forms and place columns where they could support aesthetic and programming priorities as well as walls and slabs (Thornton Tomasetti).Fig. 2 - This structural Revit model shows the large, steel-framed cantilevers of the southeast lobby. We worked closely with the architects to find patterns in the asymmetric forms and place columns where they could support aesthetic and programming priorities as well as walls and slabs (Thornton Tomasetti).

Multidisciplinary Collaboration Tamed Thermal Movement

The unified efforts of our structural and façade engineering teams helped solve the project’s biggest engineering challenge. A building 500 feet long would typically include an expansion joint to handle thermal expansion and contraction, but it would have interrupted the façade’s sleek, continuous curves. The cantilevered terrace, which supports live loads of various events throughout the year, made the challenge more complex. Together, our designers analyzed the problem and defined parameters for a solution, then worked with the entire team to find a combination of structural support, façade design and operational guidelines that controls thermal movement without sacrificing aesthetic priorities.

Construction Support Services Expedited Delivery

Our Construction Support Services practice was brought on by the steel fabricator to provide connection design and shop drawing review. Being in-house with the structural and façade designers enabled our construction support team to quickly answer questions and resolve constructability issues as they arose in the field, expediting construction.

Fig. 3 - The curved concrete walls of the auditorium support two cantilevered balconies and a double-layer roof: A concrete “acoustic lid” keeps noise out, while a more standard composite steel roof above caps off the building’s architectural form (Thornton Tomasetti).Fig. 3 - The curved concrete walls of the auditorium support two cantilevered balconies and a double-layer roof: A concrete “acoustic lid” keeps noise out, while a more standard composite steel roof above caps off the building’s architectural form (Thornton Tomasetti).

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For more information: Thornton Tomasetti

The Team

Owner University of Iowa; Design Architect Pelli Clarke Pelli Architects (PCPA); Architect of Record OPN Architects; Construction Manager M.A. Mortenson Company; MEP/T Engineer Alvine and Associates; Acoustics Kirkegaard Associates; AV Consultant Threshold;Theater Consultant Theatre Projects Consultants; Civil Engineer Shive Hattery Inc.; Vertical Transportation Lerch Bates, Inc.;Environmental Design Consultant Atelier Ten; Food Service Michael L. Bradnan & Associates; Lighting Design Cline Bettridge Bernstein; Signage Pentagram; Landscape Architects Balmori Associates and Confluence; Steel Fabricator American Structural Metals.