The Concept of Effective Stress in Unsaturated Soils - Multiscale Geomechanics: From Soil to Engineering Projects - page 154

e(p') : void ratio
(isotropic
compression test
under controlled
suction)
e s (p') : void ration
(isotropic saturated
test)

w

χ = S

Gallipoli et al. (2003)

()

=− − 11e p a b

w

ξ = fs ()1 − S

a=0.369 ; b=1.419
f(s) : suction function

1
s a

s : suction
a : parameter

χ =

Sun et al. (2003)

+

w w

Sheng et al. (2003)

χ = S r χ = S

Table 6.1. Different expressions of the Bishop χ parameter

Figure 6.1. Different approaches that can be used to solve an unsaturated
granular material problem