$3-6.$ What is the safe stopping distance for a section of rural freeway with a design speed of $80m\frac{i}{h}$ on a $2\%$ downgrade?

a$)$ a consolidated un$-$drained triaxial test was performed on a specimen of saturated clay with a champer pressure $3=2k\frac{g}{c}{m}^2.$ At failure, $1-3=2\mathrm{.}8\frac{(kg)}{c{m}^2},u=1\mathrm{.}8\frac{(kg)}{c{m}^2},$ and the failure plane angle $=57$

Calculate the normal stress and shear stress on the failure surface. You can use Mohr circle to find those values.

b$)$ The same soil specimen is now loaded slowly to failure in a drained test