The TBM boring the Hampton-Roads Bridge Tunnel Expansion project reached the halfway point, VPM reported. The 46-ft diameter variable-density Herrenknecht TBM finished the first leg of its journey under the shipping channel as it broke through the reception wall on North Island on April 17. Crews will now begin the process of rotating the TBM on a turntable before launching it back toward South Island to complete the tunneling process.

With a budget of more than $3.8 billion, the Hampton Roads Bridge-Tunnel (HRBT) Expansion project for the Virginia Department of Transportation is the largest highway construction project in the state’s history. The project involves widening the current four-lane segments along nearly 10 miles of the I-64 corridor in Norfolk and Hampton, with the new twin tunnels across the harbor. The expansion will increase capacity, ease major congestion and enhance travel time reliability.

The project represents only the fourth TBM-bored highway tunnel in the United States (Port of Miami Tunnel, Seattle SR 99 Tunnel and the Parallel Thimble Shoal Tunnel in Virginia are the others), and the second largest TBM used in the country to date (behind SR 99).

The project is being constructed via a P3 design-build contract by Hampton Roads Connector Partners, which includes Dragados USA, Vinci Construction Grands Projects, Flatiron Constructors and Dodin Campenon Bernard, with HDR and Mott MacDonald as design joint venture.