Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Coefficient of compressibility is the negative ratio of decrease in void ratio (i. E volumetric strain) to the increase in effective stress.

Increase in load will result in a decrease in void ratio and an increase in effective stress. The graph between void ratio and effective stress will be a parabolic curve with concavity upwards. The slope of this curve i.e. void ratio (y) /effective stress (x) will be negative. Hence the negative sign which will make the coefficient positive.

@neru,

Change in voids ratio is considered as strain. The strain is nothing but change in the dimension per unit original dimension.

Av = (e2-e1)/(stress2-stress1) but how strain vs stress?

I am not getting this, please Can anyone explain?

It is 1/k.

Where k=bulk modulus.

Change in void ratio is volumetric strain and change in stress is denoted as stress.

It is defined as the ratio of volumetric strain to the effective stress.

That means strain to stress.

av-----decrease strain /stress.

Here Av -coefficients of compressibility.

Av (coefficients of compressibility) -----decrease in strain /stress.

Strain by stress. Please, can anyone explain it?