Question from Soil Mechanics in Engineering Practice, 1996

[kooko]

Please refer to the attached file.
Question No. 2.
In the problem I am not quiet sure how the lowering of water below the clay layer will effect the consolidation. So far, I am assming it will create a two way drainage because of the lower piezometric head in the gravel layer.
The solution if 8 cm btw.

 

[bmike]

Use the clay parameters given to draw an e-log P consolidation "curve" (will actually be two straight lines on semi-log plot).

Calculate your intial and final effective stesses in the clay.

Pick your final void ratio off the "curve", and calculate the change in volume.