List of top Geotechnical Engineering Questions on Time rate of consolidation

For a clayey soil stratum, the time required for degree of consolidation from 25 % to 50 % is 30 days.

The total time (in days) required for 90 % degree of consolidation of the same soil stratum is (rounded off to the nearest integer).

In an oedometer apparatus a specimen of fully saturated clay has been consolidated under a vertical pressure of 100 kPa and is at equilibrium state. Immediately on increasing the vertical pressure to 150 kPa, the effective stress \( \sigma' \) and excess pore water pressure \( \Delta u \) will be