North Carolina A&T University
The new $90 million Student Center on the campus of North Carolina Agricultural and Technical State University is the university’s largest on-campus structure and a replacement for the former Memorial Student Union. The 150,000 sq. ft., LEED Silver facility includes student lounges, gaming rooms, offices for student groups, study areas, a large open atrium, the campus bookstore and six eateries. Overall, the building serves as the “heart of campus” and allows students to come together to study, eat and socialize.
"RISA-3D was clear choice due to its ability to easily add, delete or move members or boundary conditions which allowed for a seamless evaluation of multiple design iterations."
— Kristen Robichaux, PE
Because of the building’s importance on campus, the architect set out to create an iconic structure. As a result, the structural engineer was faced with the challenge of designing a structure that included large open spaces, multiple cantilevers and various load conditions based on the changing programmatic space requirements of the building. To achieve the architect’s vision, a composite steel framed system that utilized braced/moment frames for lateral load resistance was deemed to be the appropriate choice.
One of the most challenging aspects of the design was the central atrium bridge. Originally, the design called for the bridge to be completely hung from the roof. However, during the numerous design iterations the decision was made to add one central column to support the structure. Additionally, the 14ft wide stair was divided into two parts: with space for walking and space for seating. This resulted in various patterned loading conditions that all needed to be evaluated for vibration concerns. RISA-3D was used to quickly evaluate the deflection and free vibration of the bridge in order to determine how the structure would react under various pattern loading conditions as well as failure scenarios of the individual stringers or supporting column. RISA-3D was also used to model the floor height truss systems that supported the cantilevers on the 2nd and 3rd floors. Overall, RISA-3D instrumental in the design process, allowing the engineer to evaluate the required structural systems as a whole without having to break the complex elements into individual pieces.
Images 1 & 3: Mark Herboth Photography