Question

For logarithm of time fitting method, the coefficient of consolidation is detained from ________

(a) \(c_v=\frac{(T_v)_{70} d^3}{t_{70}} \)

(b) \(c_v=\frac{(T_v)_{80} d^2}{t_{80}} \)

(c) \(c_v=\frac{(T_v)_{90} d^4}{t_{90}} \)

(d) \(c_v=\frac{(T_v)_{50} d^2}{t_{50}} \)

I have been asked this question during a job interview.

I want to ask this question from Determination of Coefficient of Consolidation in chapter One Dimensional Consolidation of Geotechnical Engineering I

Answer 1

Right option is (d) \(c_v=\frac{(T_v)_{50} d^2}{t_{50}} \)

The explanation is: For logarithm of time fitting method, the coefficient of consolidation is detained from,

\(c_v=\frac{(T_v)_{50} d^2}{t_{50}}\)

where, cv=coefficient of consolidation

(Tv)50=time factor corresponding to 50% consolidation

t50=elapsed time for 50% consolidation

d=average drainage path for pressure increment.