What Does
Static Cone Penetration Test Mean?
Static cone penetration test also known as cone penetration test (CPT) is a method of geotechnical investigation for testing bearing capacity and penetration resistance of soil. This method is widely used to record the variation in the in-situ penetration resistance of soil where standard density test (SPT) is unreliable or where soil density is disturbed.
This test along with other tests is conducted prior to carrying out trenchless installation projects. The geotechnical investigation reports carry all information required to make decisions regarding the method and tools most suitable for a project.
Trenchlesspedia Explains Static Cone Penetration Test
This test is best performed in soft clay, silt, medium and fine sands and is unsuitable for gravelly soil or soil with SPT value > 50. The test is performed by pushing the standard cone with a base area of 10 cm2 and an angle of 60°, into the soil at a rate of 10 to 20 mm/sec.
After installation, a sounding rod is pushed into the soil at a steady rate of 10 mm/sec in order to advance the cone. The readings are noted in the gauge at regular depth intervals during penetration. It can also be used to measure pore water pressure, shear wave velocity and temperature.