Shear Strength Correlation

[moe333]

I'm trying to find a published correlation I can reference between percent compaction (ASTM 698) and effective stress shear strength (c', phi') for a compacted decomposed granite that classifies as SM (non plastic, >95% relative compaction, about 25% fines, minor gravel, total unit weight about 135 pcf).

Thanks

 

[dgillette]

Hi Moe. Nice to meet you in Sandy Eggo.

DM-7 has a plot that shows friction angle, RD, and material type to get phi'. Assuming 95% RC ~ 75% RD, it gives 35 for phi', but that sounds a bit conservative to me for the material you are talking about, which I expect is angular and broadly graded. I'd start with 37 and some token cohesion (maybe 200 psf).

(Thinking about the WV issue - Gail Atkinson may have published something about attenuation in the east, but I'm at a loss for site-specific w/o identified sources.)

Regards,
DRG

 

[moe333]

Dave, nice to put a face to a name. It would have been interesting to see Ray Seed speak in San Diego, but I guess it had the potential to get a little ugly, probably a wise move to avoid it.

Cheers

 

[dgillette]

I don't know if we'll ever see them in the same room without a moonlighting hockey ref to officiate.

 

[Bluefoot]

Strength correlation reference:

Granular material: RC% vs phi'
see Wong and Duncan (1974), Hyperbolic Stress-strain Parameters for Nonlinear Finite Element Analysis of Stresses ans Movements in soil Masses.

Compacted Cohesive Soils: RC% vs c',phi'
see US Department of Interior (1973), Design of Small Dams

Other referencesr vs phi'
see Meyerhof (1956), Penetration Tests and Bearing Capacity of Piles
Meyerhof (1976), Bearing Capacity and Settlement of Pile Foundations

 

[Bluefoot]

Additionally, studies have been carried out by Charles and Watts (1980), Billam (1971), Bolton (1986), Barton and Kjaernsli(1981) and Maksimovic (1989) on rockfill materials. These are discussed in Advances in Rockfill Structures by Maranha das Neves.

 

[moe333]

Bluefoot, thanks for the references, I'll look into them.