Joe Hobbs, Lankelma Technical Manager.
The cone penetration test (CPT) involves pushing a cone penetrometer – the cone – on the end of a series of rods, vertically into the ground at a constant rate of 20mm per second, to depths of up to 100m.
The forces on the cone and the friction sleeve above are measured every 20mm to obtain detailed information about the soil conditions (CPT is suitable for a range of soil but cannot be used in rock).
Results are available almost instantly and can be used to determine soil parameters including soil type, soil density, insitu stress conditions and shear strength for use in geotechnical design. For instance, CPT results can be used directly for piled foundation design in sands and gravels.
The most common cones used are the standard cone and the piezocone, the latter measuring porewater pressure. You can see our full range here. A number of special cones are also available that can be run concurrently with the standard cone test to cope with different geological environments, to evaluate a huge range of soil parameters, as well as to take samples and install geotechnical instrumentation.
The advantages of CPT
To learn more, watch our Introduction to CPT video
We’re here to help
We are always looking at new ways to help clients and partners, so please get in touch if you want to discuss how we can work together to share ideas and develop solutions to your geotechnical challenges.