A direct shear test has been carried out on a clay sample

normally consolidated, it has been seen that the maximum applied stress $(80\mathrm{.}53$ kPa$)$

corresponds to a deformation of $8$mm$,$ when the effective normal stress

corresponded to $139\mathrm{.}48$kPa. A CU triaxial test was carried out on the same sample with

an effective confining pressure of $200$kPa. In the same way, a

unconfined compression test and it was determined that the shear strength in

undrained state corresponded to $50$kPa.

a$)$ Determine the deviatoric stress at which the sample tested in the triaxial test

CU will fail.

b$)$ The pore pressure in the unconfined compression test at the time of

failure.

c$)$ The shear strength in the undrained state of the clay sample if known

that the magnitude of the sensitivity is $2\mathrm{.}3.$