Regional operator has begun field work for the six-mile Bay Area Rapid Transit extension into downtown San Jose and Santa Clara, Calif.
The information the transportation authority aims to sort out is regarding the geological conditions and locations of utilities in the path of the future project, officials said.
Officials said more information is needed to evaluate the types of soil and where current underground utilities are located to advance the design of the BART tunnel, stations and related facilities.
“Geotechnical investigations provide important details about underground soils and involve drilling and extracting soil samples to test,” a statement explained.
The equipment required to carry out the work includes a truck-mounted drilling rig and a cone penetration test truck. Each geotechnical investigation site will take up to five days to complete.
Utility investigations are also expected to reveal the precise locations of underground utilities such as water, power, communications and sewer lines.
A truck-mounted, high-powered vacuum is set to remove a small amount of soil around each utility, while truck and drilling equipment will generate ambient level noise equivalent to a lawnmower. A surveyor will note the exact location and then the small hole will be backfilled. A number of these will be performed in one location over a day span. The pavement will be replaced and the crew will move to the next location.
Officials added that workers are expected to be in the field throughout the project corridor through late 2018.
The field work is has been coordinated with local stakeholders and others located near the planned work.