Given are the following details pertaining to a preloading project:

Surcharge: Dp $=80$ kPa

Consolidating soil:

w $=50\%$; wl $=71\%($liquid limit$)$; Ip $=47\%($plasticity index$)$

$=1\mathrm{.}7$ t$/$m$3$; Cc $=0\mathrm{.}7$; Cv $=0\mathrm{.}6$ m$2/$year; Ch $=1\mathrm{.}2$ m$2/$year

L $=20$ m $($longest drainage path$)$; d $=0\mathrm{.}10$ m; S $=2$ m $($triangular spacing$)$

a$)$ Determine the average consolidation ratio Uvr $($combined vertical and radial drainage$)$

after $10$ months of preloading.

b$)$ Calculate the settlement obtained after $10$ months with and without drains