The only thing to fear is shear itself.
Don't fear the shear. Soils lab from yesterday. The shear line is almost a perfect example of what is suppose to happen.
We are getting into Mohr-Coulomb_theory .
Direct shear lab: http://1drv.ms/1hjYPr6 homework 8: http://1drv.ms/1o7QtkT
Text book examples: tex book .PDF