Contractor: J. F. White, Slattery, Perini, Joint Venture
Contract Value: $378 Million
Description: Major Urban Highway/Tunnel Construction

In April of 1997, the construction of a $378 million portion of Boston's massive CAT project was awarded to a joint venture of J. F. White, Slattery, and Perini. The C15A1 contract, involving only 1/4 mile of Interstate 93 mainline tunnels, was complicated by a maze of tunnels connecting I-93 to the surface and to the existing East Boston tunnels. A complex system of underpinning for the existing elevated central artery, countless utility relocations, and convoluted phasing to maintain vehicular and pedestrian traffic would add to the difficulty.

The extreme geometric complexity of the project prompted the joint venture to engage our services to support project personnel in untangling one of the most difficult civil works projects ever undertaken. As the project evolved, our services expanded to include:

• Development of 2-D CAD models and Digital Terrain Models to drive layout, steel detailing, formwork, lift drawings, etc.
• Development of 3-D CAD models for visualization and interference detection.
• Constructability review for support of excavation and traffic decking.
• Resolution of countless numerical errors on contract documents.
• General CAD and civil geometric support.
• Shop drawing review.

Completed on time, the C15A1 project proved to be one of the most profitable contracts on Boston's "Big Dig".