8.9 SETTLEMENT OF UNSATURATED COHESIVE SOIL
Unsaturated cohesive soil can also be subjected to a significant amount of settlement. If the cohesive
soil is near ground surface, it may become desiccated and hence susceptible to expansion and this
will be covered in Chap. 9. Usually the compression curve for unsaturated clay does not have linear
recompression and virgin compression indices such as shown in Fig. 8.2. As an alternative to using
Eqs. 8.11 to 8.14, Eqs. 7.13 and 7.14 can be used to estimate the settlement due to a building load.
An example of laboratory test data for an unsaturated cohesive soil is presented in Figs. 8.18 to
8.20, as follows