Cone Penetration Testing (CPT)
Gregg Drilling has been providing cone penetration testing (CPT) services throughout California and projects world-wide for over 20 years. Gregg’s skilled and knowledgeable operators can retrieve data at a faster rate even in difficult conditions, allowing less time on the job and a lower cost to the client. Our highly trained staff can then provide you with the technical support necessary to accurately interpret the cone penetration data we provide and assist you in the design of your site investigation program.
CPT is a process whereby soil characteristics are determined when a cone penetrometer is driven into the subsurface. The CPT provides a rapid, reliable and economical means of determining soil stratigraphy, relative density, strength and hydrogeologic information (static and dynamic pore pressure, hydraulic conductivity).
- Detailed hydrogeologic profiling at an average rate of 400 to 500 feet per day - rapid and cost effective
- Provides a near continuous log of the site lithology
- Real-time data enabling an accurate, on-site, lithologic subsurface representation
- Ideal for sands, silts, clays, soft soils and mine tailings
- Provides piezometric data in addition to geotechnical design parameters
- Add-ons such as seismic, resistivity, UVIF and gamma modules provide additional data
- Sensitive fine-grained soils
- Organic soils
- Silt mixtures
- Sand mixtures
- Gravelly sand to sand
- Very stiff sand to clayey sand
- Very stiff fine-grained soils
Gregg has also aided in the design of specialty modules and samplers that can be deployed with the CPT to obtain additional data pertinent to geotechnical and environmental investigations.
- Piezocone Penetrometer (CPTu)
- Seismic Cone Penetrometer (SCPT)
- In-situ hydrocarbon screening using ultraviolet optical screening tool (UVOST)
- In-situ resistivity and hydraulic conductivity analyses (EC and HPT)
- Membrane Interface Probe (MIP) with CPT
- Ultra-violet Induced Fluorescence (UVOST) with CPT
Gregg Drilling has effective, state-of-the-art equipment available to apply direct push technology. When applicable, this method allows for the collection of high-quality samples in less time and at lower cost. Unlike conventional drilling, direct push technology does not generate soil cuttings which, if contaminated, require special handling and costly disposal. Geotechnical and environmental samples can now be obtained in previously inaccessible areas and with minimal site impact thanks to the small limited access rigs operated by Gregg.
Gregg operates a range of truck and track mounted, and limited access direct push sampling rigs. Our direct push rigs are capable of handling both single and dual tube sampling. Gregg also owns and operates several combination drill/direct push rigs that can be converted from the direct push mode to the hollow stem auger mode when direct push refusal is encountered. This gives our clients the opportunity to meet project objectives without having to mobilize a second rig.
Gregg provides the following direct push services:
- Soil, soil vapor, and groundwater sampling
- Cone Penetration Testing (CPT)
- Injection for remediation
- Hydraulic profiling tool (HPT) with electrical conductivity
- Instrumentation Installation