Question $3$

$($a$)$ Using the stress discontinuities shown in Figure Q$3$ derive a lower bound solution for the undrained bearing capacity of the surface strip footing in terms of the undrained shear strength Su$.$ You may not use an abbreviated solution method and you are expected to draw or sketch accurately the Mohr's circles showing, i$)$ all relevant angles

with necessary construction lines, ii$)$ the poles of each circle, and iii$)$ the locations on the Mohr's circles of the stresses on each discontinuity $($there is no need to calculate the values$).$

$[12$ marks$]$

$($b$)$ Show on a sketch of Figure Q$3$ made in vour answer book, the orientations and directions of the normal and shear stresses on each discontinuity. $[4$ marks$]$

Figure Q$3$ Assumed stress discontinuities beneath the foundation

Hi there $,$ please solve parts $($a$)$ & $($b$)$ please $!$ Please do not attempt if you do not understand the question