VTA’s BART Silicon Valley Phase II Project is a six-mile, four-station extension that will bring BART train service from Berryessa/North San José through downtown San José to the City of Santa Clara. The Phase II Project will include an approximately five-mile tunnel, two mid-tunnel ventilation facilities, a maintenance facility and storage yard, three underground stations (Alum Rock/28th Street, Downtown San José, Diridon), and one ground-level station (Santa Clara). The subway tunnel will be in one large diameter tunnel.
Single-Bore TunnelThe tunnel will be constructed as a single, large diameter tunnel. The approximately 45 foot tunnel will contain two independent trackways, one for each direction of travel. Passenger platforms will be located within the tunnel, connected to station entrances via underground passageways. Depending on the station, platforms will be approximately 66 and 85 feet below ground.
Within the tunnel, there will be emergency egress points spaced every 300 to 600 feet that will allow passengers to reach non-affected areas during an emergency situation. The tunnel will be excavated with a Tunnel Boring Machine (TBM) at an average depth of 60 feet. At stations, soft ground mining techniques will be used to excavate the underground connections between the tunnel (which contain the boarding platforms) and the off-street station concourses.
How does a Tunnel Boring Machine (TBM) Operate?A tunnel boring machine (TBM) is a large drill that excavates and installs the initial tunnel lining that supports the tunnel needed for the train to travel underground. The front section of the TBM (the cutter head, seen in photo below on the left) chips, grinds, and removes the dirt.
• Within the large hole created, precast concrete segments will be installed to form rings to support the tunnel. The precast rings will be sealed to prevent water and mud from seeping into the tunnel.
• Soil will be removed via launch portals and either hauled away or reused for the project.
• The TBM will be powered by a temporary electric substation and will enter and exit the tunnel through either of the portals.
• Once the TBM has completed digging the tunnel, the track and facilities can be installed. The specific type of machine and path of travel will be determined as the project progresses.
Continued on the reverse side
Twin-BoreRunning Tunnel
Single-BoreRunning Tunnel
UtilitiesUtilities
Up to ~60'Up to ~60'
Up to ~75'Up to ~75'
• Mined cross-passage for emergency evacuation between tunnels
• Sliding re door for emergency evacuation between tracks when side-by-side
March 2018
Track Con gurations in Running TunnelVTA’s BART Silicon Valley Phase II Extension Project
Istanbul Straight Road Project
VTA’s BART Silicon Valley Program Overview
VTA is extending the BART regional heavy rail system to Milpitas, San Jose, and Santa Clara. The 16-mile extension, called the BART Silicon Valley Program, will extend the BART system south of BART’s future Warm Springs/South Fremont Station in Fremont to Milpitas, San Jose, and Santa Clara. When completed, this fully grade-separated project is planned to include six stations and a new maintenance and storage facility in Santa Clara. VTA’s BART Silicon Valley Program is being delivered in two phases. The Berryessa Extension Project (Phase I) is under construction and scheduled to open in 2018, with stations in Milpitas and the Berryessa area of San Jose. The Phase II Extension Project (Phase ll) will include a 5-mile-long subway tunnel through downtown San Jose and will extend the BART system from the future Phase I terminus for approximately six miles to the City of Santa Clara. Four stations are proposed for Phase II: Alum Rock/28th Street, Downtown San Jose, Diridon, and Santa Clara.
Phase II SchedulePublic Review of Draft Environmental Document (SEIS/SEIR)..................... December 2016 through March 2017
Preparation of Final SEIS/SEIR .................................................................... March 2017 through January 2018
Release of Final SEIS/SEIR........................................................................... February 2018
VTA Board Approves Project......................................................................... April 2018
FTA Approves Project.................................................................................... June 2018
Construction Begins...................................................................................... 2018
Passenger Service......................................................................................... 2026
FACT SHEET: BART Silicon ValleyVTA’s BART Silicon Valley Phase ll Extension Project
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VTA BART Ext Phase ll 021418
FACT SHEET: VTA’s BART Silicon Valley Phase II Extension ProjectTunneling Methodology
How will the community be impacted during construction? The single-bore tunneling methodology reduces construction impacts over traditional methods by conducting most excavation without disrupting the street. However, a major construction project like the Phase II Project will have impacts to the community. For example, during construction, including utility relocations, there will be sidewalk and lane closures as well as contained impacts at the station entrances, portals and ventilation structures. VTA will continue to work with the cities of San José and Santa Clara, the construction contractors, the public, and local residents and businesses to minimize impacts to the extent possible. Major project construction is expected to start in 2020.
Taylor RdMcKee Rd
13th St 19th St11th St
10th St
4th St
1st St
Market St
24th StE Santa Clara St
W Santa Clara St
W Hedding St
N 1st St
Coleman Ave
NOT TO SCALE
N
Mineta San Jose
International Airport
Newhall Maintenance
Facility
680
680
280
880
87
87
101
101
880
Phase I AlignmentPhase II Ground-Level AlignmentPhase II Single-Bore Tunnel Alignment
LEGEND
13th Street Ventilation Facility
East Portal (Typical Portal)
West Portal (Typical Portal)
Typical Underground Station
Stockton Avenue Ventilation Facility
SANTA CLARA STATION
DOWNTOWN SAN JOSÉ STATIONDIRIDON STATION
ALUM ROCK/ 28TH STREETSTATION
BERRYESSA/ NORTH SAN JOSÉ
STATION
VTA’s BART Silicon Valley Phase II Extension ProjectDraft Recommendations July 2018
VTA’s BART Silicon Valley Program Overview
VTA is extending the BART regional heavy rail system to Milpitas, San Jose, and Santa Clara. The 16-mile extension, called the BART Silicon Valley Program, will extend the BART system south of BART’s future Warm Springs/South Fremont Station in Fremont to Milpitas, San Jose, and Santa Clara. When completed, this fully grade-separated project is planned to include six stations and a new maintenance and storage facility in Santa Clara. VTA’s BART Silicon Valley Program is being delivered in two phases. The Berryessa Extension Project (Phase I) is under construction and scheduled to open in 2018, with stations in Milpitas and the Berryessa area of San Jose. The Phase II Extension Project (Phase ll) will include a 5-mile-long subway tunnel through downtown San Jose and will extend the BART system from the future Phase I terminus for approximately six miles to the City of Santa Clara. Four stations are proposed for Phase II: Alum Rock/28th Street, Downtown San Jose, Diridon, and Santa Clara.
Phase II SchedulePublic Review of Draft Environmental Document (SEIS/SEIR)..................... December 2016 through March 2017
Preparation of Final SEIS/SEIR .................................................................... March 2017 through January 2018
Release of Final SEIS/SEIR........................................................................... February 2018
VTA Board Approves Project......................................................................... April 2018
FTA Approves Project.................................................................................... June 2018
Construction Begins...................................................................................... 2018
Passenger Service......................................................................................... 2026
FACT SHEET: BART Silicon ValleyVTA’s BART Silicon Valley Phase ll Extension Project
Continued on reverse side
VTA BART Ext Phase ll 021418
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