VTA BART Silicon Valley Extension Phase II
The largest single public infrastructure project ever constructed in Santa Clara County, the BART Silicon Valley Phase II will extend BART service 6-miles from the Berryessa Transit Center into downtown San Jose and into the City of Santa Clara.
For the first mobilization in 2022, Gregg Drilling completed boreholes in downtown San Jose with Pressuremeter, vane shear and SPT energy testing up to a maximum depth of 150ft. Vibrating wire piezometers were installed in boreholes after collection of geotechnical samples. Additional mobilizations in the spring and fall of 2023 included a similar scope of work with the deepest borings extending to 260ft as well as sonic borings up to 160ft with continuous sampling. Deep CPTs with seismic tests were completed along the route extending up to 150ft.
Highlights/Challenges:
- Rotary & sonic drilling and geotechnical sampling
- Advanced specialized testing (PMT, VST, Energy Calibration)
- Deep seismic CPTs to 150ft
- Traffic control & street work in downtown San Jose
Success story: Gregg Drilling was able to provide a large portion of the contract value as a Disadvantaged Business Enterprise (DBE) for this contract.
From Carolina Zamora, Shannon & Wilson: “I wanted to let you know that it was a real pleasure working with Jarred, Clay, and Amando. They were honestly the best drilling crew I have worked with in a long time (probably ever) and certainly the best crew I have worked with at Gregg. They were friendly, hard-working, and competent, willing and able to answer all my and [our client’s] questions. They kept to the schedule and most importantly did so safely, amidst the chaos of downtown and all the other hurdles we had to jump over.”
Download the full project profile in PDF.