ABSTRACT
One of the most important differences between saturated and dry soils on the one hand and unsaturated soils on the other, is that saturated and dry soils both have a single phase pore fluid, whereas unsaturated soils have a two-phase mutually soluble pore fluid. For a saturated soil, the effective stress equation is:
σ I = σ − uw (1.2)
For a dry soil, it is:
σ I = σ − ua (2.1)
As shown in Chapter 1, for unsaturated soils the Bishop form of effective stress equation is:
σ I = (σ − ua) + χ(ua − uw) (1.2b)
This chapter will explore the validity of eqn. 1.2b and show how the Bishop parameter χ and the Fredlund parameter ϕ b may be evaluated. Index and compaction properties for the various soils mentioned in the text have been listed, in order of appearance, and as known, in Table 2.1.
