The model is a combination of the member, surface, and solid elements with several releases and hinges to absorb tolerances and accurately model the slotted holes. The front T-sections (posts and beams) are modeled with member elements, and the outriggers with solid elements to ensure correct force distribution between the front beam elements and the secondary supporting structure. The stirrups are displayed as surface elements.

In the locations where bolts intersect surfaces or solids, average regions have been defined to properly distribute the stresses. The anchor points utilize the concrete surface’s pressure points to withstand the large downward force due to self-weight. At the fixed supports, spring stiffnesses were defined to determine the allowable concrete stress and the tensile force acting on the Halfen channels. Difficulties arose in the roller point supports due to the relatively thin concrete slab of only 8 inches, which was solved by modifying the direction of the slotted holes in stirrups.

Facade Engineering:
Rümmele Bauingenieur GmbH
www.ruemmelefacades.com