East Side Access Project makes use of modular Precast Concrete Components
The East Side Access project, which will cost more than $10 billon is one of the largest mass transit project in the country. The first expansion of the Long Island Railroad (LIRR) in more than 100 years, it will transport passengers from Queens and Long Island directly into Manhattan. One of the major construction initiatives is the construction of mined caverns under the existing Grand Central Terminal (GCT) for the new passenger rail station.
In addition to the track work, construction in the GCT Station includes fabrication and construction of the permanent structural concrete lining, interior structures, and fit-out of the cavern spaces. The scope of work includes structural precast fit-out of two 1000-foot existing caverns with 830 precast beams, 844 precast panels, 694 precast walls, and 370 precast platforms.
Cavernous Effort
Working on two enormous 1, 143-foot-long caverns carved out of solid rock 100 feet beneath GCT is not without its challenges. When the project is complete, the caverns will hold more than 3,300 precast concrete elements including beams, deck panels, platform walls, and slabs manufactured by The Fort Miller Co., Inc. and installed by Tutor Perini.
To make delivery of the precast as efficient as possible, Fort Miller trucked pieces to storage yards in Long Island City. They were then hauled into the cavern on a designated rubber-tire route (along which train tracks will lie in the future) on the same flatbeds used for ground transportation to avoid double-handling of the elements.
Maneuvering cranes to pick each piece as well as the flatbed trucks under hook within the tunnels and caverns posed its own challenge. “From a logistics standpoint, building this train terminal within an existing mined cavern is like building a ship within a bottle,” says Joshua French, Vice President of Sales and Estimating, The Fort Miller Co., Inc.
Archi-Structural Mix
The precast mix design balanced the structural requirements while allowing for an exposed architectural finish in the mezzanines. The thousands of precast elements were fabricated using white and gray concrete mixes along with smooth and sandblasted finishes to meet the aesthetic conditions.
Fort Miller engineers completed a total of 462 custom shop drawings for 313 unique precast component mark-numbers. All precast elements were poured using 28 different types of wood and steel forms, most of which were fabricated in-house.
The fabrication of over 3,300 structural and architectural precast concrete components were an integral phase of the massive MTA East Side Access Project, slated to be completed in 2022, that will benefit more than 300,000 commuters who use the LIRR each day.
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