A new tunnel is to eliminate a bottleneck in the major construction project of the Chesapeake Bay Bridge-Tunnel in Virginia. Near the city of Norfolk in the US state of Virginia, the Chesapeake Bay Bridge-Tunnel connects the Hampton Roads region and the Delmarva Peninsula (belonging to Delaware, Maryland, Virginia). It is structured as follows: Over a length of 37 kilometers, bridges and tunnels alternate between four artificially raised islands.
A Herrenknecht TBM of the type Earth Pressure Balance Shield (EPB) and with a diameter of 13,210 mm undercut the seabed and created the new tunnel of 1,936 meters in length parallel to the existing Thimble Shoal Tunnel. Two additional lanes are being built in the new parallel Thimble Shoal Tunnel so that traffic can pass undisturbed under the Thimble Shoal shipping channel to reach the respective bridge section and vice versa.
Special demands were placed on the EPB shield “Chessie” with a drive power of 7,000 kW and 46,183 kNm of torque: It should be particularly robust, especially in the area of the excavation tools, in order to minimize the need for compressed air entries as much as possible. Another challenge at the start and end of the advance was the low overburden in the area of the man-made islands, where large boulders can also be found.
Before the TBM was handed over to the customer for assembly with the support of Herrenknecht Service in the USA, two project managers from Herrenknecht were working on it simultaneously. Steffen Dubé, President and General Manager of the Herrenknecht subsidiary in the USA, emphasizes: “Not every project is the same. With the Chesapeake Bay Bridge Tunnel, we unavoidably had to deal with a high level of complexity. We made up for it with the customer's trust and extra service.”
Michael Kimmeskamp, member of the management of the Traffic Tunnelling division and responsible for its project management, adds: “The project has shown once again: service starts with project management.”
Herrenknecht subsidiary H+E Logistics was involved in transporting the excavated material from the jobsite onto ships.
