$70 million addition/renovation to existing art museum. Two piece aluminum panels were formed into three foot, nine inch square boxes by riveting a weather-proof insulated aluminum panel backing to a decorative stamped and expanded aluminum panel. The boxes are supported by a unitized aluminum tube system.
Unique Challenges
No way to analyze the stamped and expanded aluminum boxes for wind and ice loads.
Impossible to use the unitized aluminum tube system to support all the panels due to odd shapes and corners of the building.
The manufacturer’s shop drawings for the tube framing system called for the anchors attaching the panels to be located next to the splice between the frames requiring large moment connections between the tubes.
Solution
Larson hired a company to test maximum wind, ice and cyclical wind loads to determine what effects fatigue would have on the boxes. Panels were supported with plates attached to the ends of the aluminum tubing not disrupting the decorative panels. Larson recommended shifting the anchors up 8 to 10 inches, away from the splices. This put the splices at a point of zero moment and eliminated the need for a moment connection. In turn, this allowed the aluminum tubes to be 1/16 inch thinner, saving more than 12,000 pounds of aluminum over the entire project!
