Coupled Consolidation of Layered Unsaturated Soil under General Time-Dependent Loading

It is crucial to estimate the behavior of layered unsaturated soils with time-dependent loading for several reasons, including (1)construction of a building is a time-consuming process and loading on the soil can be altered over time, and (2)the soils found in nature are often unsaturated and layered. There are two different approaches for analyzing the soil consolidation, namely coupled and uncoupled approaches. The coupled approach is considered to be more difficult, but more valid because this approach involves an association between stress-strain analysis and the process of excess pore fluid pressure dissipation; whereas in the uncoupled approach, the analyses are conducted separately for these two phenomena. In this study, the theory of one-dimensional coupled consolidation for layered unsaturated soils is solved under different boundary conditions and general time-dependent loading through the incremental differential quadrature method (IDQM) by assuming both water and air phases are continuous. The research demonstrated that the IDQM is able to easily solve the coupled consolidation theory for layered soils under complex loading conditions. (C) 2018 American Society of Civil Engineers.