What Does Standard Penetration Test (SPT) Mean?
A standard penetration test (SPT) is carried out in soils where it isn't possible to bring out an undisturbed sample, such as in weak rock, silt, clay, sand and gravel. The test provides an indication of the relative density of the granular deposit and its approximate shear strength. A standard penetration test can also be used for cohesive soils to determine its unconfined compressive strength. The procedure is simple and is inexpensive, making it a widespread test method for geotechnical subsurface soil investigation.
Trenchless technology utilizes methods such as horizontal directional drilling (HDD) and pipe ramming to install pipes below ground surface and hence these tests are an integral part of soil investigation prior to carrying out the trenchless procedure.
