TYLin provided civil and structural engineering design services for Phase 1 of the Bay Area Rapid Transit (BART) line extension from the Warm Springs Station in Fremont to northern San Jose in California.
Linking the South Bay with the heavily used commuter train, the 10-mile extension connects Santa Clara County residents to the existing 131-mile BART system and the cities of San Francisco and Oakland. The system is expected to have an average weekday ridership of 46,000 by 2030.
The BART Berryessa Extension included two new stations, each of which is part of new multimodal transit centers located in Milpitas and Berryessa.
As the Principal Engineer for a joint venture team, TYLin’s work for the design-build project included the design of the aerial guideways, trench structures, the Sierra-Lundy tunnel, rail bridges, grade separations, retaining walls, sound walls, roadways, and traffic signal systems.
The entire project was constructed on an alignment acquired from and adjacent to active Union Pacific Railroad (UPRR) tracks, requiring a fully grade-separated operation.
- For the grade-separated operation, eight locations were established where a combination of the following were developed and designed by TYLin:
- 13,000 linear feet of retained cut undercrossing 800 linear feet of cut-and cover tunnel
- 800 linear feet of cut-and cover tunnel
- 3,300 linear feet of elevated guideway overcrossing
- TYLin provided the design of the Berryessa Station Way Bridge and a bridge over UPRR industrial lead track.