Mixed Foundation Solutions: The Answer to Supporting New Towers over Existing Subway Tunnels

From the Brooklyn Bridge to the towers that define the Manhattan skyline, designing foundations for New York City's urban landscape has always challenged engineers. Sometimes challenges arise due to site constraints, geologic conditions, or the client's desire to maximize the footprint and height of the structures while minimizing costs. This paper discusses two projects, located within several city blocks of each other, where all of the mentioned challenges created a "perfect storm" of sorts for the designers. The Owners, Architects, Structural Engineers, Geotechnical Engineers and Foundation Contractors collaborated to address the combined design and construction needs and achieve a cost effective foundation solution that met the project goals. Mueser Rutledge Consulting Engineers (MRCE) was involved in the two projects.