What is CPT Testing?
Cone Penetration Testing (CPT) is fast, safe, and instantly offers digital in situ soil behaviour type (SBT). The in situ data gathered can inform geotechnical design and field characterization decisions immediately. CPT’s versatility in obtaining shear wave velocity, sediment pore pressure dissipation, and discrete sampling offers users increased functionality and digital-sounding files.
Cone Penetration Testing (CPT) is not only highly accurate, but it is also relatively inexpensive compared to other testing methods. In fact, it is three times faster than SPT site characterization, which triples productivity and reduces underived waste generated (cuttings).
The data generated can be exported and utilized in multiple modelling software to accurately assess risk in design and inform geotechnical decisions. CPT data offers high-resolution in situ results versus SPT, which often utilizes variable intervals and limited grab samples from various depths.
An excellent option for soil testing is Vertek’s S4 CPT Sounding System. It’s a cost-effective push system that works well with construction equipment and comes with a dedicated trailer system. The S4 offers exceptional soil testing capabilities, making it a suitable alternative to SPT Testing in almost any location.
Additionally, if your organization utilizes SPT for site characterization, a small capital investment into a CPT Drill Rig Conversion Kit allows you to quickly conduct CPT testing and offer both services to your customer.
The Federal Highway Administration even notes CPT is one technology that allows
“optimization of subsurface exploration programs for improved site characterization and maximum return-on-investment.”
What is SPT Testing?
The Standard Penetration Test (SPT) is an affordable geotechnical examination method. It helps determine the angle of shearing resistance, cohesionless soils’ relative density, and stiff cohesive soils’ strength.
Mud rotary drilling, for example, has come up in the past along with one of the best-known soil testing procedures: the Standard Penetration Test (SPT). Like Cone Penetration Testing, SPT Testing is widely used. But can it outperform CPT Testing?
The Standard Penetration Test (SPT) employs a notably thick sample tube to determine the density of granular deposits such as sand and gravel. This allows for accurate measurements of the soil’s resistance to penetration, which can then be used to determine its relative density.
To conduct a soil test, a sample tube is placed at the base of a borehole and hit repeatedly with a heavy slide hammer. The number of strikes required to drive the tube 6 inches into the soil is noted by the operator. The test concludes when the tube reaches a depth of 18 inches. This process requires precision and accuracy.
It’s easy to see why a test that only needs a sample tube and a hammer would be advantageous – it’s straightforward and cost-effective.
While SPT Testing can be useful, it has limitations that must be considered. In particular, this technique may not be as precise as more advanced methods, particularly when dealing with materials such as coarse sand or clay. On the other hand, CPT can offer a faster and more efficient way to conduct seismic soundings. Hence, it’s crucial to thoroughly weigh the pros and cons of each method before deciding which one to employ for a specific project.
The Final Word from Vertek
As President and Principal Engineer of GEOLINES, Otto Holmquist stated, “Every time a geotechnical engineer sees how efficient it is, they are hooked.”
Whether you prefer to click the link or dial 1-800-639-6315, we’re here to help you discover the perfect solution for your needs. Let’s discuss your requirements and find the right fit together.