I am a Polish student of English and I am currently trying to translate a publication on pile design. While reading the article I came across an abbreviation SPT (in a collocation 'SPT data'). I don't have the slightest idea what it can mean and I cannot find it in any dictionary. I would be very grateful if somebody could explain to me what theese letters stand for.
To further elaborate, the Standard Penetration Test(SPT) is a test method wherein a 2 inch (50.8mm) diameter split-tube sampler (nominally 18 to 30 inches [.46 to .76m] in length)is driven into the subsurface using a 140 pound (63.5 kg)weight dropped 18 inches (.46m). The test method is usually performed on a drillig rig equipped to perform auger and/or core drilling.
The SPT test has been around for a long time, and as discussed by the previous response, the results of the SPT test have been correlated to many angineering properties, including shear strength and high-strain Shear (Gmax) and Young's modulus of soils. One note; as all in the forum are probably aware, modulus correlations related to the SPT are tenuous at best; comparison with modulus data derived from geophysical testing (Vs and Vp) often indicate substantial differences in modulus data caluclated from the geophysical data as compared to modulus data infererred from SPT correlations.
If i can add some contribution, usually the correlation tables regard single grain fraction (sand, clay etc.): in Netherland SPT tests are rather reliable but what really happen in heterogeneous terrain like ligurian deposits? The values are approximate a lot and much scattered; clay SPT Shearing resistence can be unreliable (see, for example, Lambe and Whitman, 1997). Besides, sub aquifer top measured shot number N' is correct to N = 15 + 1/2 (N' - 15), introducing further errors. Therefore the risults just should be considered orientative or tainted by other tests.