ABSTRACT
Settlement Calculation from e-p Curves We can plot the field e-p curves from the laboratory test data and the field e-Iog p curves. The weight of a structure or of a fill increases the pressure on the clay stratum from the overburden pressure Po to the value Po + ~p (Fig. 7.11). The corresponding void ratio decreases from eo to e. Hence, for the range in pressure from Po to (Po + ~p), we may write
av (cm2 / gm) = 2p(cm / gm) (7.12)
(7.13)
is called the coefficient ofcompressibility. For a given difference in pressure, the value of the coefficient of compressibility decreases as
the pressure increases. Now substituting for ~e in Eq. (7.8) from Eq. (7.12), we have the equation for settlement
aHS =_v-1ip=m H ~p t l+e v
where m v =a
v /(1 + eo) is known as the coefficient of volume compressibility.
