Time factor for a clay layer is

Question

Question

This question was previously asked in

BPSC AE Paper 5 (Civil) 14 Oct 2022 Official Paper

Answer 1

Concept

The time required for any degree of consolidation can be obtained from Taylor's formula, it is a dimensionless parameter

Tv = Cv × t /d2

Where,

Cv = Coefficient of consolidation is constant for the same type of soils,

Tv = Time factor will also remain constant for the same degree of consolidation.

Thus, Time Factor depends on Coefficient of consolidation, Drainage path & Time.

Important Points

The time factor is given by,

For consolidation less than 60 %

\({T_v} = \frac{\pi }{4} \times {\left( {\frac{U}{{100}}} \right)^2}\)

For consolidation greater than 60 %

\({T_v} = 1.781 - 0.933{\log _{10}}\left( {100 - U\% } \right)\)