Consolidation Rate Analysis Using Finite Difference Method

A $3-$m thick clay layer, drained at its upper surface and the base, is subjected to a rectangular distribution of initial excess pore water pressure of $200$ kPa $.$ The $c_v$ values of clay is $\frac{1}{3}\frac{m^2}{?}$ year. By dividing the layer into $6$ equal slices, determine the average degree of consolidation after one year.

Assume $t=3$ months.