Urban Below-Grade Engineering: Excavation Support and Foundations for Expanding the American Museum of Natural History

The Gilder Center for Science, Education and Innovation (SEIC) is the newest expansion of the landmarked American Museum of Natural History (AMNH), and will function as a state-of-the-art scientific and education institution. Bold and modern architecture define the five-story structure, which includes a 6-m deep cellar level. The about 4,500-sq-m footprint of the SEIC is adjacent to seven museum buildings, each built between 40 and 130 years ago. The general subgrade for the SEIC cellar was up to 2-m below the lowest levels of the adjacent buildings, and involved localized excavations for new foundations and mechanical pits extending up to 3-m below the lowest levels. Excavations for footings and pile caps, up to 6-m below the proposed cellar level, were adjacent to active utility lines servicing the museum. Shallow groundwater and layers of thick clay and highly weathered bedrock further complicated the foundation support and temporary excavation support design and construction. The approach to the SEIC expansion of the iconic museum, located in a historic neighborhood with vast differences in subsurface conditions across the project site, could only be achieved with a variety of foundation types and excavation support and underpinning systems, coupled with careful inspection.