Question

The coefficient of consolidation from square root of time fitting method is calculated from the equation _________

(a) \(c_v=\frac{(T_v)_{90} d^2}{t_{90}} \)

(b) \(c_v=\frac{(t_{90})_{90} d^2}{T_{90}} \)

(c) \(c_v=\frac{(T_v)_{90} d}{T_{90}} \)

(d) \(c_v=\frac{(T_v)_{90} d^3}{t_{90}} \)

The question was asked in a job interview.

This intriguing question originated from Determination of Coefficient of Consolidation topic in chapter One Dimensional Consolidation of Geotechnical Engineering I

Answer 1

Right option is (a) \(c_v=\frac{(T_v)_{90} d^2}{t_{90}} \)

Best explanation: The coefficient of consolidation is calculated from the equation of,

\(c_v=\frac{(T_v)_{90} d^2}{t_{90}}, \)

where, cv=coefficient of consolidation

(Tv)90=time factor corresponding to 90% consolidation

t90=elapsed time for 90% consolidation

d=average drainage path for pressure increment.