Friction Angle Correlations 1

[moe333]

Is anyone aware of a published correlation that relates friction angle to a percent compaction for a predominantley granular soil. If there is something out there I would think it would be specific to a range of gradation.

 

[dgillette]

The old standby, DM-7. In the '75 edition, it's Fig. 3-7. It has a family of curves from which you can estimate phi' as a fn. of relative density (but not percent compaction).

It shows, for example, phi' for SW ranging from 27 deg at RD=0, to 37 at RD=75, to 41 at RD=100. Believe the trend, but not the specifics, since it's all dependent on coeff of uniformity, particle angularity...

Presumably these are peak rather than phi-cv, which I would expect to be more nearly constant with RD.

 

[moe333]

Thanks, I am familiar with that reference, but I was looking for the correlation with percent compaction.

 

[BigH]

But wouldn't the correlation be related to a host of factors? - gradation of the material, angularity (crushed faces), which type of compaction? Sure you have thought of this. Phi of a 98%MDD(std) for a Atlantic City beach sand would be much different than 98%MDD(std) using a crushed granular base course. Would have to find correlations for "groupings". I haven't seen any - although, one might be able to backtrack knowing the CBR values - which are based on % compaction.