Simplified Computation of 1D Consolidation for Unsaturated Soil when Air Phase Neglected

Abstract

It is a complicated problem for consolidation analysis of unsaturated soils. Nowadays’ theories are very theoretical, and the parameters in them are so many that it is difficult to solve the equations, i.e., they are not excellently fit for application in engineering. So it is significant to get a simplified theory for consolidation analysis of unsaturated soils. In this paper, according to the phenomena observed in consolidation’s experiments for unsaturated soils, it is assumed that pore-air pressure undergoes an instantaneous dissipation and the consolidation of unsaturated soils can be described as the process of dissipation of excess pore-water pressure. Then a simplified consolidation model is put forward. And based on the principle of the whole soil mass conversation, the continuity equation is founded. Subsequently one- dimensional consolidation equation is derived, which is similar to Terzaghi’s equation for consolidation of saturated soils. Finally, the numerical results from the derived equation are compared with the experimental results from laboratory tests reported in the literature, and the agreement is good. It can be concluded that the hypothesis is rational and the simplified computation is practical in engineering.