$12\mathrm{.}16$ The time for $50\%$ consolidation of a $25mm$ thick clay layer $($drained at top and bottom$)$ in the laboratory is $225s.$ How long $($in days$)$ will it take for a $2m$ thick layer of the same clay in the field $($under the same pressure increment$)$ to reach $50\%$ consolidation? There is a rock layer at the bottom of the clay in the field.