Geotechnical Drilling for San Benito U.S 101 Pavement Rehabilitation Project

Geotechnical Drilling for San Benito U.S 101 Pavement Rehabilitation Project

This CECE was completed for geotechnical investigative drilling operations at 24 locations along U.S 101 in San Benito County from post mile 0.4L to 6.4 within Caltrans right-of-way. Caltrans Drilling Services or consultant drill crews, under the supervision of a C-57 license holder, will perform geotechnical drilling using truck-mounted, trailer-mounted, or all-terrain drill rigs weighing between 28,000 and 48,000 lbs. The drilling equipment will include a Standard Penetration Test (SPT) hammer, along with support equipment such as a water tender, crew cab, and geologist/engineer vehicles. To obtain quality soil samples, hollow stem auger and mud rotary drilling systems will be used, with borings ranging from 4 to 8 inches in diameter. When the hollow stem auger reaches its limit, the rig will switch to mud rotary coring, requiring drilling fluid (water mixed with bentonite clay or liquid polymer) to stabilize the boring and bring drill cuttings to the surface. The borings will be backfilled with cement or a cement-bentonite slurry, and groundwater levels will be measured if encountered. The SPT will involve driving a thick-walled sample tube into the ground to correlate soil properties with blow counts. After drilling, the crew will clean the mud tank and any remaining drill cuttings, disposing of them in 55-gallon drums, and rinse any residue from paved surfaces with minimal water use.

Aromas, CA, San Juan Bautista

San Benito

Countywide