Standard Penetration Test blow counts do not Standard Penetration Blows a simple physical property of the soil, and thus must be correlated to soil properties of interest, such as strength or density. Although it is widely used, there are some important limitations that I have to mention.
The Standard Penetration Test (SPT)
STANDARD PENETRATION TEST (WITH VIDEO)
Send us an email to editor geotechdata. The SPT is a field test which should be used as a general guide only.
Standard Penetration Test - alfasat.info
Standard penetration test - Wikipedia
Although it is widely used, there are some important limitations that I have to mention. You should check with the Standard Penetration Blows guidelines in your area, but I will provide the following procedure just so it is not left as a vacuum: