The Lincoln Tunnel is a vital link between New York and New Jersey. An extensive network of approaches connects the tunnel to the transportation network on either side of the Hudson River. A previous study conducted in 1999 determined that some of these approach structures may be vulnerable during seismic events. Modjeski and Masters was commissioned to study in more detail six of those structures. These included:

• Bus Ramps Over 9th Avenue

• Galvin Avenue Structure

• Galvin Plaza Structure

• Helix Structure

• Bridges Over Park Avenue

• Bridges Over Marginal and JFK Boulevard

The scope of work called for the analysis of two design cases:

1. Allows bridges to remain elastic under the design seismic event and to be immediately opened to traffic afterwards.

2. Ensures the bridges will not collapse during the design seismic event. However, inelastic deformations are allowed during the design seismic event. This approach requires structures to be inspected after the design seismic event and may require immediate emergency repairs before opening them to traffic.

Furthermore, Modjeski and Masters performed the following:

• Record Search - Consists of acquiring as-built and any subsequent rehabilitation plans

• Computer Modeling - Using the plans and other pertinent data collected during the Record Search, SAP 2000 or Seisab computer models were developed.

• Developed Retrofit Concepts and Costs - Concepts and cost estimates were developed for the two scenarios listed above.

• Prepared a Report of Findings