One-dimensional consolidation of unsaturated fine-grained soils

In this study, one-dimensional consolidation of fine-grained soils is considered. By taking into account the results of the infiltration theory, a new approach, which is applicable to soils in either saturated or unsaturated conditions, is given. After definition and review of the relevant quantities, the general differential equation of one-dimensional consolidation is derived on the principle of equating the work done by the internal and external forces. The resulting equation is a nonlinear partial differential equation, from which the classical linear equation of consolidation can be obtained by assuming the coefficient of consolidation to be a constant. In order to verify the theoretical results of the proposed approach, an experimental study was also performed, and the findings were compared with those given by the classical theory. The sorptivity, which is a rather new definition in soil mechanics, suddenly increases when the primary consolidation ends, and this phenomenon provides an opportunity to determine the coefficient of consolidation otherwise computed by the log-time method. © ASCE