The effective stress paths $($ESPs$)$ generated from $5$ consolidated$-$undrained $($CU$)$ triaxial tests, conducted on $5$ identically prepared specimens of kaolinite, are given $($next page$).$

All $5$ specimens were subjected to a triaxial compression $($TC$)$ stress path until the soil reached critical state.

Given the nature of CU triaxial testing, the undrained shearing stage $($carried out under constant mean stress $\backslash ($ p $\backslash ))$ was initiated after consolidating the specimens to initial effective mean stress $(\backslash ($ p$^\{\backslash$prime$\}\backslash ))$ values of $\backslash (50,100,200,400\backslash ),$ and $800$ kPa $,$ respectively.

The effective stress paths would be virtually identical if the samples were to be subject to a conventional triaxial compression $($CTC$)$ stress path, as illustrated $($following page$).$ The build$-$up in pore$-$water pressure, however, would be higher under a CTC stress path, given that the initial confinement would be kept constant throughout the undrained shearing. For the same set of $5$ consolidated$-$undrained $($CU$)$ triaxial tests described in Exercise $3$:

$($A$)$ Draw the total stress Mohr's circles to exact scale, as conceptually illustrated $($next page$),$ and determine the undrained shear strength parameters $\backslash (\backslash$boldsymbol$\{$c$\}\backslash )$ and $\backslash (\backslash$boldsymbol$\{\backslash$varphi$\}\backslash )$ for the soil.

NOTE: Include the corresponding calculations of total principal stresses.

$($B$)$ Draw the corresponding effective stress Mohr's circles to exact scale, as conceptually illustrated $($next page$),$ and determine the drained shear strength parameters $\backslash (\backslash$boldsymbol$\{$c$\}^\{\backslash$prime$\}\backslash )$ and $\backslash (\backslash$boldsymbol$\{\backslash$varphi$\}^\{\backslash$prime$\}\backslash )$ for the soil.

NOTE: Include the corresponding calculations of effective principal stresses. Figure $(\backslash ((\backslash )$ Total and effective stress failure envelopes for consolidated undrained triaxial tests. $($Note: The figure assumes that no back pressure is applied.$)$