Three structures connected by 4-story bar, 3-story 600-car underground garage; Vierendeel frame, up-up construction; 8-foot ceilings, 10-foot floor-to-floor height. LEED Silver. 235,000 sf.

Weidlinger Associates was the structural engineer for a new Harvard University residential complex for 350 graduate students, which provides 1.5 acres of open space along the Charles River. The 235,000-square-foot building comprises a 5-story, L-shaped low-rise wing, a 15-story, mid-rise building, and a 3-story, 185-foot-long Vierendeel frame “bridge” of apartments that connects the two structures and is elevated approximately 45 feet to create a covered terrace below. This innovative design reduced the overall height of the building; allowed for a continuous flow across the courtyard, terrace and expansive lawn; and increased open space and river views.

To ensure the pedestrian-friendly character of the neighborhood, Harvard spent an additional $34 million to create a three-level, post-tensioned 600-car underground parking garage, which is accessed from an existing, adjacent parking garage, rather than building a comparable above-ground structure. A ground-level steel structural system translates the grid spacing for the steel frame residential superstructure onto the larger grid spacing for the parking garage.

Weidlinger overcame several structural challenges. The "bridge" of apartments was required to connect two buildings with different lateral force resisting systems and stringent facade performance criteria. Construction of the new underground parking facility required underpinning the existing above-ground parking structure while operations were maintained. An up/up sequence expedited superstructure construction by making it independent of the concrete garage construction. The foundation system consists of 2-foot-thick perimeter slurry walls, individual spread footings, and mats bearing on natural marine clay. The project was completed on time and within budget.

Completion Date: 2003
Location: Allston, Massachusetts
Owner or Client: Harvard University
Prime Consultant(s): Machado and Silvetti Associates