Effective angle of friction

Effective angle of friction deg deg (T- Resihting axial stress in pow der kg/cm- psf... 

Effective angle of friction deg deg Cz Resulting axial stress in powder kg/cm ... 

Undrained shear strength = Effective unit weight of soil = Strain at 5 - level = Pile diameter = Penetration = Correction coefficients = Effective angle of friction 9 ... 

The above equation is plotted as maximum slope angle (a) as a function of the excess pore pressure ratio (ue/y z) and effective angle of friction (( )) (Figure 11.13). For a cohesionless material the maximum slope angle (a) increases with increasing effective angle of friction ((()) but decreases with increasing excess pore water pressure ratio (rj. 

Note ko = — sin ) (where is soil effective angle of friction). 

The angle p is related to the effective angle of friction p and the wall angle of friction p = arctan f by ... 

Figure 1.17 Yield loci for the determination of Jenike effective angle of friction (S) (a) and internal angle of friction (5e) (b) from the critical state line (CSL) (fc unconfined yield stress and cti major consolidation stress).

The Jenike effective angle of friction is the angle of the straight line drawn through the origin of a normal stress-shear stress plot and tangential to the Mohr semi-circle, which inscribes the equilibrium, or end point of the yield locus when failure occurs at no sample volume change. The Mohr semi-circle represents the stresses in a powder consolidated under a major principal stress. 

---