Silman provided comprehensive structural engineering services for the renovation and expansion of Smith’s main library, including the design and detailing of two feature stairs. Like many long-established campus spaces, the 1909 structure had undergone numerous piecemeal alterations over the years. Silman’s first task was the careful excision of two eras of additions followed by renovations to the main building interior. This preliminary work paved the way for restoring the original design and creating more inviting central library spaces.
Because the project’s large-scale modifications triggered a seismic lateral system retrofit, Silman designed a new system of steel braced frames located just inside the existing masonry bearing walls. These new frames are supported on a new foundation system of pile caps and grade beams.
The new construction consists of two “jewel box” wings located to the north and south of the original H-shaped library. The south wing holds special collections, archives, and rare books; the north wing includes learning spaces, a café, and a digital media hub. The jewel boxes comprise steel frame and composite slab construction with continuous curved steel ring beams supporting a series of reinforced concrete walls to define the window openings. Silman designed the steel framing to accommodate over 800 MEP penetrations.
A site with clay soils and a high water table required creative foundation solutions. Instead of dewatering or excavating the existing clay layer, which would have significantly impacted the overall project schedule and costs, the project team installed new pile foundations at the south basement by locally drilling through the existing mat slab and using the new pile caps to help resist hydrostatic uplift. This project also replaced the basement roof slab and part of the top of the foundation wall with new landscaping and a basement roof structure buried below grade.
Despite the increase in overall interior floor area, the project team managed to decrease the building’s footprint by about 25%, returning lost green space to the adjacent grounds in alignment with Frederick Law Olmsted’s original 1893 design. The Neilson Library renovation project, now LEED Gold certified, is part of a larger Smith College campus library master plan.