60%\({T_v} = \frac{π }{4} \TIMES {\left( {\frac{U}{{100}}} \right)^2}\) For consolidation greater than 60%\({T_v} = 1.781 - 0.933{\log _{10}}\left( {100 - U\% } \right)\)Calculation:For 25% consolidation, U ≤ 60 %\(\begin{array}{l} {T_v} = \frac{{\rm{\PI }}}{4}{\left( U \right)^2}\\ = \frac{π }{4} \times {\left( U \right)^2} = \frac{π }{4} \times {\left( {0.25} \right)^2} \end{array}\)Tv = π/64