Particle Size Analysis for small SPT Soil Sample with Gravel

[learning2geotech]

If a SPT soil sample has a piece of 3/4 gravel and the sample volume is small, do you include the gravel in the Particle Size Analysis? If it is included, its weight may be too dominant, throw off the curve, and the soil type result may not be representative. What would you recommend to do in this case?

 

[geotechguy1]

Was the soil above and below the SPT logged / photographed? How many similar pieces of gravel were observed in those locations? What about in nearby boreholes?

 

[MTNClimber]

It depends. What is the purpose of your gradation analysis? To confirm visual classification or for design reasoning? Ultimately, you could just leave it out of the sieve analysis and note that it was omitted on the lab test results and logs.