Basic 1D settlement

[drew1482]

Hi,

A simple equation for primary settlement is:

primary settlement = (change in void ratio)*(depth of soil)/(1+ e0)

If you consider a small element of soil, the equation seems to suggest that as the initial void ratio, e0, increases, the amount of settlement will decrease. I would have thought that as the void ratio increases the settlement would also increase. Can someone explain? Thanks.

-Andrew

 

[oldestguy]

Remember you apparently trying to compare two situations, for a given stress increase.

In the real world, applying a given stress increase to a same thickness layer for two different soils, one with high void ratio and the other with a lower void ratio, the delta e resulting is much higher for the high void ratio condition as compared to the low void ratio condition. This change is much greater than the (1+e) difference.

Thus, the resulting answer explains why high void ratio soil compressed more than the low void ratio material.

Ya gotta look at both top and bottom parts of the equation.

 

[drew1482]

Got it. Thanks.