The new Ismaili Center uses a contemporary design incorporating large open atrium spaces. The large open spaces are framed with structural steel while the majority of the remaining structure is concrete. The Prayer Hall is an open outdoor space with plan dimensions of roughly 110’x110’ and 40’ tall. The floor structure of the Prayer Hall is supported on deep plate girders arranged in a diamond pattern. This supports built-up plate columns in the form of a star that are 40’ tall which carries the roof framing that uses a framing layout in the form of triangles. There is no lateral force resisting system as part of the steel structure because the floor and roof level use cast-in-place concrete diaphragms which will not be installed until several months after steel erection is complete. The Atrium uses stacked planar Vierendeel trusses to create a large tall open space. Similar to the Prayer Hall, lateral bracing and stability are provided by cast-in-place concrete slabs that will not be installed until well after erection is complete. The construction engineering aspects of this project required careful review of the partially completed structure of the Prayer Hall and Atrium, the design of fabricated temporary bracing, and lifting of heavy trusses. The unique geometry, missing load path, and long term schedule created engineering challenges for the partially completed structure.
Source: NASCCYear: 2024