A point within an embankment slope of sand has a total vertical
normal stress (y) of 100 kPa, a total horizontal normal stress
(x) of 60 kPa, a horizontal shear stress (xy) of 20 kPa, and a
pore water pressure of uo. The sand has a peak effective friction
angle of 30 degrees. (a) Determine the value of uo that would cause
the sand to fail in drained shearing. Assume the total normal
stresses and shear stress remain constant. (b)...