Dynamic Cone Penetrometer Testing for Soil

by Bryan Gee, P.E., on June 12, 2019

The Dynamic Cone Penetrometer, or DCP, is one of the most efficient and effective tools available for testing the strength of soils on site. It is also used to monitor the condition of granular layers and subgrade soils in pavement sections over time. Tensar and our partners routinely use dynamic cone penetration testing to help our customers determine the right solutions for their sites, especially when soft soils are involved.

The DCP test method uses a simple instrument that can be easily carried wherever it is needed. It consists of a standard diameter steel rod, a hardened conical tip, and a standard weight hammer which is dropped from the top of the rod against an anvil to advance the tip into the ground.


DCP Testing, Instrument Picture


To use the DCP test device, the hammer is raised to the top of the rod and released in order to drive the rod into the ground. Using the vertical scale, the dynamic cone penetration (in inches or millimeters) of soil is recorded after each blow of the hammer. This measurement has been correlated against standard measures of soil strength, such as the California Bearing Ratio (CBR).

Examples to Watch:


There are several benefits to testing with dynamic cone penetration on your job sites, including:

  • Soil information is often limited, and often collected mostly where building foundations will be, but you may need to assess the soils somewhere else on the site.
  • You can get information on how the soil strength varies with depth, which can be critical to developing the best solution for unsuitable subgrade soils.
  • You can collect information from a lot of points relatively quickly, so you can see how soil conditions vary across the site and respond accordingly.
  • You get accurate information on the soil conditions in the field and at construction time.


Tensar’s field team and many of our distributors are equipped with Dynamic Cone Penetrometers (DCPs) and prepared to help you with assessing your site and developing potential solutions. If you’d like to schedule a site visit, including DCP testing if appropriate, contact us.

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If you’d like to learn more about assessing soil conditions and options for stabilizing unsuitable soils, check out our most recent Tensar Professional Education webinar: "Assessment of Poor Soil Conditions and Effective Stabilization Solutions"

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