BIM + IPD: 三个成功案例(一) （转）
EMPAC: A Theater in a Bottle
In 2004, Turner Construction was hired to manage the construction of EMPAC, a showcase for the latest in performing arts technology at the nation's oldest technological higher education institution, Rensselaer Polytechnic Institute. An international architectural competition led to the selection of the London/New York firm Grimshaw to design the new center.



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The entrance to EMPAC is at the top of a hill on RPI’s Troy, N.Y., campus. The difficult site was chosen not just for its views of the Hudson Valley, but also because it’s a main thoroughfare for students. Photo: Turner Construction



Grimshaw's conception of a glass building encasing a double-curved sculptural wooden hull—the theater itself—created the kind of bold, technologically and architecturally forward-thinking statement that RPI wanted. The budget and program were also ambitious: $160 million for a 221,200-sf performing arts center that included a 400-seat theater and 1,200-seat concert hall and exceptional requirements for acoustics, theatrical and media presentation, structural integrity, lighting, and HVAC.

Representatives from Grimshaw, exterior woodwork designer Richard Herskovitz, AIA, of Architectural Woodwork Industries (AWI), Philadelphia, and the construction team from Turner met to discuss how they would get from conceptual design to delivery.

"From our side, everyone recognized how difficult this was going to be," said Stephen Coates, project manager for Turner. "The owner was willing to pay up front for 3D modeling. All the parties realized that because of the complexity and the shape of the building, 3D modeling was the only way this project was going to get done on time."




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The wood hull, roof, north curtain wall columns and outriggers, and the acoustic panels for the concert hall and studios of EMPAC were all modeled entirely in 3D before the project broke ground. The construction of the project was coordinated across all disciplines using this model. Models: Architectural Woodwork Industries and Grimshaw Partners



Herskovitz, a principal at AWI who had previously modeled the millwork for the interior of the Boston Convention Center and Verizon Hall in the Kimmel Center for Performing Arts in Philadelphia, recommended that the entire design team collaborate using BIM and virtual construction software to solve problems. The architects from Grimshaw had been modeling the building for more than a year in Rhino, a 3D modeling program that can calculate the mathematical information for complex forms, such as the NURBS (non-uniform rational B-splines) surfaces at EMPAC. On Grimshaw's recommendation, Rhino was jointly chosen to model most of the project. Rhino can calculate any point on a complex curve with a high degree of accuracy. The program could also handle the task of turning Grimshaw's artistic curves into steel and wood panels and connections. It could also generate 2D slices of the shell model which would later be used to develop the space plans of the building.

"The most important thing is the methodology," Herskovitz said. "We didn't particularly need parametric modeling. What was more important was that everyone was involved early in the design process."

Four months of interaction between the architects, structural engineers, steel designers, and subcontractors followed. Architects from Grimshaw, led by partners Andrew Whalley and Mark Husser, and architect of record Davis Brody Bond, New York City, modeled the entire building in Rhino. AWI collaborated in detailing and working out the complex shapes of the cedar-planked hull around the EMPAC Concert Hall. The team's steel design firm, Supermetals Structures, Quebec, created the building's exterior steel skin model in SDS/2, a 3D program that can export files in the IGES file format. The New York office of consulting engineer Buro Happold created a full-building 3D MEP model.




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With a 40x80-foot stage and computer-controlled rigging, EMPAC’s theater is equipped to the highest standards. The ceiling is made of panels of Nomex fabric less than one millimeter thick for optimum acoustics. Photo: Paul Rivera/Archphoto



AWI helped coordinate all the work of the subcontractors by integrating it into one final model. Missed connections, poorly placed anchor points, and clashes were discovered in the unified Rhino environment; the team was able to visualize and solve problems before construction began. Using Rhino also allowed the Building Team to break up curved geometries into discrete parts and number and organize them for fabrication and installation. This enabled steel fabricator Radius Track to prefabricate all the curved steel framing and bent metal studs from its shop in Minneapolis.

The concert hall required displaced ventilation with large-volume, low-frequency air distribution from under the floor. The design team found a way to snake huge underfloor air distribution ducts through the hull structure in the 3D model. Without modeling the ducts and fabricating them offsite, it would have taken much longer to deliver the complex MEP network in EMPAC, according to Turner's Coates.

Last October, EMPAC opened on time and on budget, with very few construction changes, none of which increased costs. For $160 million and no overruns, Rensselaer got the state-of-the-art, architecturally significant performing arts center it had wanted all along. The university is applying for LEED Silver certification.

"The model coordination was very high at every level on EMPAC," said Shane Burger, a Grimshaw associate and head of the firm's computational design unit. "Everything we modeled was analyzed by the entire team with both aesthetic and functional questions asked throughout the process, and that level of coordination has become the baseline for all our future projects."