padding on the ground at west portal area
Cost-Saving Revision Advances BARTSV Tunnel Work
12/12/2024

The Santa Clara County Transportation Authority (VTA) Board of Directors took another major step in advancing VTA’s BART Silicon Valley Phase II Extension Project by authorizing an amendment to the Kiewit Shea Traylor Joint Venture’s (KST) Tunnel and Trackwork Contract (CP2) to facilitate preparatory efforts and construction of the large shaft structure from which tunnel boring machine (TBM) will be launched.  Beginning construction of this TBM launch structure is a critical step to maintain the project’s estimate and schedule of 2037 passenger service date. 

construction prep work for BARTSV west portal
Construction preparation for BARTSV West Portal

The value of the newly authorized KST amendment, not exceed $366,357,987, reflects a $15 million negotiated reduction from the contractor's last estimate.  Construction of the launch shaft will be executed concurrently with the custom manufacturing of the TBM which is already underway, ensuring site readiness to tunnel boring in 2027.

“When we put our shovel in the ground in February, we’ll be taking the biggest step yet toward building our 5-mile tunnel” Stated Tom Maguire, VTA Chief Megaproject Officer.

CP2 is being executed in two stages, and this work is part of the first stage authorized by the Board in May 2022. Other work in the first phase includes investigation of cost saving and delivery innovations, programming and design services, procurement of the TBM, demolition, utility relocations, and other early site and general preparatory and construction activities. Stage 2 of CP2 would be for all remaining tunnel related work, including construction of the tunnel, concrete structures in the tunnel, portals, station shafts and tunnel connections, underground boarding platforms and trackwork. As shared with the Board, a decision and suggested path forward on Stage 2 will be shared in the first quarter of 2025.

On June 12, 2024, VTA broke ground at the site of the future Santa Clara Station, which will include the station, rail and maintenance yard and tunnel’s west portal where the TBM will be launched from and ultimately where passenger trains will descend to or ascend from the five 5-mile tunnel. To date work at the site has included site grading, drainage, utility relocations, constructing on-site access points, crew parking and offices, and construction fencing. Upcoming work includes installing a noise curtain to protect nearby residents and businesses, building the launch shaft, constructing a tunnel liner factory and storage area, excavated material bin and a grout plant to make the sealant for tunnel liners.

VTA’s extension of the regional BART system is the largest transportation infrastructure project in the history of Santa Clara County, Calif. The project will integrate Santa Clara County with the greater Bay Area BART system, enhancing regional connectivity and providing numerous economic, environmental, and social benefits.  Future near-term milestones include advancing overall design and securing $5.1 billion through the Federal Transit Administrations New Starts Funding Program via a full funding grant agreement outlining the timing and amount of allocations.

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