Silicon Valley Rapid Transit Project/BART

16.3 mile extension

Tunneling in a dense urban environment

USD 6 billion in project costs

Challenges

It was necessary to extend the BART system into downtown San José to provide a transit alternative to the highly congested I-680 and I-880 commuter corridors.
San José was then able to become connected with the rest of the San Francisco Bay area.
The extension meant that tunneling was needed through a dense urban environment in soft fluvial soils.

Hatch (in JV) was responsible for designing the tunnel segment: the alignment, tunnel lining and cross passage (CP) design, settlement analysis and mitigation, coordination with BART facilities standards, station interfaces, cost estimating, construction sequencing, and specification of owner-procured tunnel boring machine (TBM) and lining systems.
We also were responsible for project management support services, project cost control, maintaining a trend log and estimating changes, performing independent cost estimates of proposed changes, and schedule controls for the entire Silicon Valley Rapid Transit project.
Extensive geotechnical investigations included 101 borings, 179 cone-penetrometer tests, and six pumping tests.

The BART extension will provide alternate transit options.
It will reduce traffic congestion and eliminate approximately 16,000 tons of greenhouse gases in a year.
It will also provide support for development along the length of the corridor.
Overall cost and schedule-control management were seamlessly provided for a highly complex transit project.