1. Part 3 Behavior of Overconsolidated Clay

2. Normal versus Overconsolidated clay behavior Clay retains a “memory” of its load history The effective cohesion of overconsolidated clay can be significant The effective cohesion can be lost through subsequent wetting, especially, load cycling with moisture

3. Mohr Circle plot of a typical overconsolidated clay soil, illustrating the artificially high cohesion engendered by tortuous desiccation. Note the apparent preconsolidation pressure caused by the severe shrinkage.

4. The fundamental problem with slabs-on-grade on expansive soils is differential swell beneath the corners, sides, and under the center of a uniformly-loaded slab, as sketched here.