Shani Wallis, TunnelTalk

Hatch Mott MacDonald (HMM) and Bechtel Infrastructure Corp in joint venture are selected for tunnel design and construction management of the Bay Area Rapid Transit (BART) extension to Milpitas, San Jose and Santa Clara in Silicon Valley.

The Santa Clara Valley Transportation Authority (SCVTA) selected HMM/Bechtel in late November and award of contract is scheduled for its February 2004 Board meeting.

The Silicon Valley Rapid Transit extension will comprise 16.3 miles (26km) of third-rail system, seven stations, and a maintenance/storage facility, with 4.5 miles (7.2km) and four stations underground beneath downtown San Jose (Fig 1).

Line construction is scheduled to begin in 2006 and be turned over to BART for revenue service in late 2013. HMM/Bechtel's portion of the program includes preliminary and final design and construction management of the 4.5-mile underground section and its proposed four underground stations. It also includes project controls for the full 16.3 mile extension from BART's future station at Warm Springs to the future Santa Clara station near Mineta San Jose International Airpport.

Fig 1. Underground section of the extension

After studying the Sheppard Subway project in Toronto, Canada and the rail tunnel project under the Saint Clair River between Canada and the USA in the mid/late 1990s, owner SCVTA recognized the value of owner-procured machines and tunnel lining. Like those projects, on which HMM was engaged as project designer and construction manager, the TBMs and the precast concrete tunnel lining system needed for the BART extension will be procured by the client and made available to the successful contractor.

"Client procurement of these major items will save at least a year on the construction program," said Gordon Smith of HMM. "It also takes the element of TBM design and procurement risk out of the contractor's bids, ensuring better prices." Smith is appointed HMM/Bechtel Project Manager responsible for all aspects of the contract. Alastair Biggart of HMM will manage client procurement of the two TBMs needed for the project. Other key team members include John Hawley (HMM) Tunnel Segment Design Manager, Ted Livingston (Bechtel) Project Controls Manager, and Chris Dixon (Bechtel) Deputy Project Manager/Construction Manager.

More than half of the estimated $3.8 billion cost of the extension will be funded through the 30-year 1/2 cent sales tax transit levy passed by local taxpayers in November 2000. In August, the VTA Board approved sale of up to $550 million in bonds, secured by and payable from the sales tax revenues. Part of this will carry the extension project through the preliminary design phase. An application to the Federal Transportation Administration is expected to request 22% in FTA funding and the California state government is being asked for a 17% contribution. A 'comprehensive agreement' signed with BART establishes the framework for project implementation and operations.

Jack Collins, Chief Construction Officer for SCVTA said: "The Hatch Mott MacDonald/ Bechtel JV brings experience in design and construction of transit tunnels relevant to the soft ground conditions found in downtown San Jose."

References

BART to San Jose - TunnelTalk