Geotechnical Site Investigation
Every sound foundation starts with knowing what is actually in the ground. Our site investigations combine track-mounted drilling, cone penetration testing (CPT), and test pits with continuous sampling, so design decisions rest on measured data rather than assumptions. Samples are logged and lab-tested in-house, and preliminary results are available within 24 hours of fieldwork.
What's included
- Track-mounted and truck-mounted drilling to design depth
- Cone penetration testing (CPT) for continuous soil profiling
- Test pits and hand-augured borings on access-restricted sites
- Continuous sampling with SPT blow counts and undisturbed tubes
- In-house laboratory testing (gradation, Atterberg, consolidation, shear)
- Groundwater monitoring and observation wells where required
What you receive
- Boring logs and CPT profiles
- Laboratory test data package
- Subsurface cross-sections
- Geotechnical data report ready for design or peer review
When you need it
You need a site investigation before design on any structure that transfers load to the ground — new buildings, additions, retaining walls, and hillside projects. Most Bay Area jurisdictions require a geotechnical report for permit submittal, and lenders increasingly ask for one before closing.
Site Investigation — common questions
- How long does a geotechnical site investigation take?
- Fieldwork for a typical residential or small commercial site takes one to two days. Preliminary boring logs are available within 24 hours, and the full data report usually follows within one to two weeks depending on the lab program.
- What is the difference between borings and CPT?
- Borings recover physical soil samples for lab testing and let us measure SPT resistance at set intervals. CPT pushes an instrumented cone continuously, giving a high-resolution soil profile without spoil. We often combine both for the most complete picture.
- How deep do the borings need to go?
- Depth depends on the structure's loads and the soil profile. Light residential structures may need 15–25 feet; larger buildings, deep foundations, or liquefiable sites can require 50 feet or more. We size the program to the project.
Related services
Tell us about your site.
Send us the location and what you have planned. You'll get a straight answer on what the ground can carry — and a fixed-fee proposal within 24 hours.