He is also the technical brains behind ProjectEngineerthe online project management system for engineers. Corrections Although the field-tested N-value should be reported on the borehole logs, many corrections have been suggested that are in common use today.
The borehole is drilled deeper and the test is repeated. Not using correct weight Driller frequently supplies drive hammers with weights varying from the standard by as much as 10 lbs.
8:44
The Standard Penetration Test (SPT)
9:25
Hydrostatic pressure can cause sand to rise within the casing.
2:58
The basic problems to consider are change in effective stress at the bottom of the borehole, dynamic energy reaching the sampler, sampler design, interval of impact, penetration resistance count.
5:3
Standard Penetration Test (SPT) a Basic Soil Testing Procedure