Questionable Result from CUP Triaxial Test

[learning2geotech]

See attached photo. Phi effective is 39 degrees. The result seems questionable because it is very high for this soil, which is silty sand, at 8ft depth, and has a N-value of 4. Based on the lab report, where do you think the lab procedure went wrong?

 

[morecoffeeplz]

Where to start?

What's the Gs of this material? The water content and densities seem suspect. Also, it was sheared too quickly.