On 26/08/2022 a joint committee of VTA and BART Board members will discuss the evolving design of the VTA’s BART Silicon Valley’s extension project into San Jose and Santa Clara: click here. The 9.65 km (6 mile) project includes 8.05 km (5-mile) tunnel and 4-stations, three of which underground.
As part of the design process, the tunnel and trackwork contractor, Kiewit Shea Traylor (KST,) is exploring and analyzing dozens of changes that could result in more efficient delivery and ultimately enhance the project. These ideas take into consideration the cost and construction timeline, as well as safety, operations and maintenance, and passenger experience.
Side by Side Tracks in One Tunnel
One of the key proposed ideas includes a center boarding platform within the single bore tunnel (meaning, a platform between both directions of tracks) for all three underground stations – 28th Street/Little Portugal, Downtown San Jose, and Diridon Station.
This design idea would allow for:
- side by side tracks for the entire 6-mile extension
- a shallower descent to the platform from the street level
- potential access to the boarding platforms from both sides of Santa Clara Street, in Downtown San Jose
VTA and its contractor are using a delivery approach to the project that allows for more engagement and ongoing collaboration with key stakeholders and the community as the design advances before construction begins. During this “design innovation” period, VTA is working with a task force of public and private transportation professionals to identify potential station refinements. These efforts could enhance access to stations, promote Transit-Oriented Development, and spur economic growth.
VTA is working with the American Public Transportation Association (APTA), to engage an independent review of the project’s tunneling method. Inquiries about the cutting-edge tunneling methodology, never before used on a transit project in the U.S., spurred the review. A previous independent review of the tunnel design in 2018 led to the single bore approach and current concept. The new review will include feedback from the ongoing “design innovation” work and build on work done to date, including the 2018 peer review.
More in-depth information on the innovations and station refinements will be shared at the VTA Board Workshop on September 16. For further information please visit https://www.vta.org/ and the tunnelbuilder archive us/61 and here. 34/22.
