Design development on East Side Access

The East Side Access Project of the Long Island Rail Road (LIRR) in New York will involve over 7,1000 m of tunnels that will be constructed in Manhattan and five bored tunnels in Queens, totaling over 4,000 m. Tunneling technology that will be used on the project includes tunnel boring machines (TBMs), drill and blast, road headers, raise-borers, open-cut, and pipe-jacking. This article looks at some of the geotechnical considerations involved in the project, the use of segmental tunnel lining, and the different approach structures, in particular, the Yard Lead approach structure and tunnel. The article concludes with a discussion regarding the emergency exists and how the design features an independent exit shaft for each passenger tunnel, with all five exits relocated to one centrally located bridge.