Consolidation of Compacted and Unsaturated Clays

Synopsis A review is made of published evidence on the physical properties of unsaturated and compacted clays with the object of recognising the more important factors affecting the consolidation process in such soils. An attempt is then made to formulate and solve a set of general equations to describe the consolidation process. Because of the complexity of these equations it is found desirable to sub-divide the process into a number of less general treatments, each being relevant to a particular range of saturation values. The treatments include the effects of decreasing permeability and a compressible pore fluid, and the resulting non-linear partial differential equations are solved by finite difference approximations on a digital computer. The computed results exhibit the two important characteristics found in consolidation tests on unsaturated clay, viz. a continuously curved settlement/root-time plot and a mid-plane pore pressure dissipation plot which is flatter than the theoretical Terzaghi plot. ...