Located at the heart of Salt Lake City’s financial district, at the corner of South Main and East 100 South Street, 111 Main is a Class A office tower that anchors a larger urban redevelopment project in the area. The construction of the building followed a parallel timeline with an adjacent project designed by another architect, the George S. and Dolores Doré Eccles Theater.
The office building and theater, critical elements in the city’s downtown revitalization, contribute to the development of a walkable urban core and help to create a vibrant community. The office tower is targeting LEED® Gold certification and also supports Salt Lake City’s commitment to increased urban density and long-term sustainability.
The structural engineering of 111 Main reflects an innovative solution to a complex site challenge. To ensure the project would not compromise any of the theater’s functionality, the entire structure is suspended from a steel hat truss on top of the building that allows the Eccles Theater to slide under the tower’s south side.
The lobby is enclosed by 35-foot-tall, ultra-clear, low-iron structural glass. SOM worked with the New York office of engineers Eckersley O’Callaghan to develop a sophisticated glass hinge system to meet this height requirement and mitigate seismic movement. The feature provides the office building with a high level of transparency, visually connecting its lobby interiors with the city outside.
A 35-foot glazed facade system for the expansive lobby of the newest addition to Salt Lake City’s skyline. Designed to withstand windstorms and the seismic pressures of earthquakes.
Eckersley O’Callaghan acted as the Engineer of Record for the design of the custom all-glass lobby facade system. Set back from the perimeter, the slender building core allows for an expansive lobby entrance 40 feet tall. However, this also results in significant building movements in the event of a windstorm or earthquake.
While all floor plates move together uniformly, a key challenge was presented at the interface between the hanging building and the entry-level facade, which is base-supported on the ground.
A study of movements, rotations, supports, and rigidity was conducted to define a system that would cope with the immense imposed building deflections.
A kinetic hinge system was developed to accommodate total building vertical movements of three feet, while precision linear slide bearings were employed to absorb lateral building drifts.
Large cantilever structural steel entry portals were designed integrally with the glazed facade system. Incorporation of architectural timber fins was accomplished with a novel approach to laminate wood veneer into the glass assemblies.
Detailed analysis of global movements, post-failure behaviour, and gasket and sealant flexibility was carried out as part of the delegated design requirements to ensure performance throughout the building’s design life.
111 Main’s translucent glass fin facade reflects changing light conditions as the sun traverses the sky. The structural hat truss, situated behind a graduated translucent glass veil, is also visible in the sunlight and, when backlit, appears like a glowing lantern in the night. The result is a building that adds lightness and luminosity to Salt Lake City’s skyline.