Cone Penetration Testing equipment was originally designed – and is still most commonly used – to characterize subsurface soil behavior types. But when you invest in CPT equipment, you are getting the capability to do much more. A variety of sensors and in-situ samplers can be integrated into CPT modules, making CPT equipment a versatile and efficient choice for contamination detection, environmental site assessment, and other field applications.
CPT equipment has several advantages over conventional hollow stem auger drilling and percussion drilling based methods, especially in contaminated soils. Specialized CPT tests can identify contaminants and determine the physical extent of the contamination with minimal disturbance of the soil, thus avoiding costly disposal of drill cuttings and minimizing contact between field personnel and potentially hazardous materials.
Here’s an overview of some tests and technologies that you can harness via CPT equipment:
- Temperature data is obviously useful in locating zones of different ground temperature, for example frozen soil. However, it can also help to identify soil contaminants that generate heat due to chemical or biological activity.
- Electrical Resistivity:
- The electrical properties of soil are changed when the soil is contaminated. For example, soils containing non-aqueous-phase (NAPL) compounds exhibit higher resistivity than normal, while soils containing dissolved organic compounds such as can be found in landfill leachates have significantly lower resistivity.
- Fluorescence Detection:
- Most hydrocarbons produce fluorescence when irradiated with certain kinds of light. Thus, hydrocarbon contamination can be efficiently detected by integrating LEDs of a particular wavelength (or sometimes lasers) into CPT cone modules. The detected wavelength of the fluorescent response to the excitation source is graphed in real time and is used to determine the areas of interest and further define contaminants.
- The integrated camera or video camera module can also be used to visually inspect in-situ characteristics such as color, grain size and texture of the soil in real time.
- Pore Pressure
- Most modern CPT cones are equipped with pore pressure sensors to measure the in-situ soil moisture. In addition to determining groundwater conditions, pore pressure data is helpful in determining soil behavior profiles.
- Soil, Water and Gas Sampling:
- In situations where quantifiable samples of subsurface soil, liquid or gas need to be collected for laboratory testing, the use of specialized CPT-compatible modules can speed this process. These sampling devices are compatible with CPT rod strings and push systems and eliminate the need for extra drilling equipment or providers.
Vertek offers a range of specialized CPT equipment for environmental applications, including:
- Modular Soil Sampler: This device allows you to use your CPT push system to easily and reliably obtain soil samples.
- Groundwater Sampler: This device can be utilized to collect a discrete sample from an area of interest and allows the exploration to be grouted immediately after the sample is obtained, decreasing migration.
- Grouting Modules: These devices can be attached behind the cone to tremie grout the borehole upon retraction or can be used with a specialized cone that deposits a disposable tip at the end of a sounding and grouts the annular space created during retraction.
- ConeSipper: This module attaches behind a normal CPT cone to take liquid or gas samples as the cone is pushed into the ground. Samples can be obtained from multiple depths during a single sounding, saving time and money.
- SMRT (Soil Moisture, Resistivity and Temperature) Module: This multi-purpose module can provide long-term data for applications such as irrigation or monitoring landfill sites.
- VTK Video Module: This module incorporates real-time video screening with LED hydrocarbon fluorescence detection.
Want to know more? Visit our website or download our catalog to learn more about how these products work, and how they can work for your business.