Time rate of consolidation example: average degree of consolidation and settlement.

Example that involves use of the relationship between the average degree of consolidation and the time factor for calculation of settlement at a given time and the time required for the layer to settle a given amount.
Video #14.

[@Anghel57190]

Fantastic. I love it, well explained.

[@HashemAljifri515]

Hello man when do you use this long formula for settlement and when to use the same formula but without cr parameter?

[@abduljabbarkhan9107]

Say, there are four layers below a square footing. Up to the depth of footing the soil is clay.
First layer: clay soil, thickness H1, coefficient of consolidation: Cv1
Second layer: clay soil, thickness H2, coefficient of consolidation: Cv2
Third layer: sandy soil
Fourth layer: clay soil, thickness H4, coefficient of consolidation: Cv4
The fourth layer is followed by impermeable rock.
How would you apply Terzaghi's classical formula , t = Tv/Cv*hd^2 to this problem? (hd = drainage path)
To be more specific, how can we calculate time required for 50%
consolidation of entire soil system? What will be the values of Cv and
hd for the first layer?

[@arunkandel4431]

A half-closed layer (free-draining top boundary) is 10 m thick with cv = 7.9 m2
/yr. Pore pressure measurements were
made as follows:
Depth/ m 0 2 4 6 8 10
u/ kPa 60 54 41 29 19 15
Obtain a numerical estimate of the excess pore water pressure after 1 year’s consolidation has occurred.
Can you please explain the steps for this if possible. Thanks