Cone Penetration Testing
By carrying out one or more cone probes it is possible to determine the soil profile at the project location and to compare it with what is stated in regional geologic- and geohydrologic charts, relatively cheap.
During probing, the following information can be registered with regard to your project, i.e.:
- Penetration resistance;
- Local friction;
- Pore pressure, whether or not using one or more dissipation tests;
- Electrical conductivity;
- Magnetic field;
- Inclination.
If the environmental conditions allow it, our probings are normally carried out by measurements of DGPS (x- and y-coordinate with regard to the RD-system, z-coordinate with regard to the NAP). Should there be no GPS-signal, for instance due to vegetation or buildings in the nearby area, the ground level will be measured using a levelling instrument and the location using a measuring tape. If possible the groundwater level will be measured in the probe hole.
Depending on the desired parameters, which need to be registered when the probe is carried out, the probes will be presented as follows:
- In a classical graph showing cone resistance, frictional resistance, friction ratio, pore pressure, electrical conductivity, and/or the inclination;
- As a drilling section, based on the measurements made.
The said derivation takes place as described in an article by Robertson in the “Canadian Geotechnical Journal” of 1986. This method has been further developed and described by Lunne, Roberts and Powel in their reference work “Cone Penetration Testing in Geotechnical Practice”. A derivation of the soil types based on the cone resistance and the friction ratio yields a good impression of the expected soil profile, particularly below groundwater level. It is more difficult to interpret soil types above groundwater level. Should this be significant, it is advisable to also carry out a manual drilling. If desired, this can be completed as a stand pipe piezometer.
Using the probes carried out and derivations made, it is possible to determine numerous soil parameters which, in turn, are necessary ingredients for the various geotechnical calculations that have to be made. Cone penetration testing is therefore an extremely important yet relatively cheap tool in achieving a high-quality geohydrologic or soil-survey study.
BMNED has a wide range of equipment at its disposal being able to respond to almost any situation, both on land and water.
Here you can find some action shots from probing activities on land.
Please contact us for more information or a free quote.
We will be more than willing to answer all your questions.
BMNED, your geotechnical and civil engineering company!