ABSTRACT
As soils are loaded or unloaded isotropically (i.e. with equal all-round stresses) or anisotropically they will compress and swell. As we saw in Chapter 6, volume changes in saturated soils involve rearrangement of grains together with breakage of weak sand grains and swelling or compression of clay grains accompanied by seepage of water as shown in Fig. 8.1. Volume changes occur in unsaturated soils as air is expelled. Compression of unsaturated soil is important mostly during compaction of excavated soil in to embankment fill. This is described in Chapter 26.
