Analytical Solution for One-Dimensional Consolidation of Soft Soil Induced by Water Head Difference

The one-dimensional consolidation of soft soil induced by water head difference between the top and the bottom of the soil layer was studied. One-dimensional consolidation equation expressed by water head under arbitrary datum plane was derived, and the general solution was obtained for arbitrary decline model of water table. Furthermore, for two simple models which are linear decline model and instant decline model, formulas were obtained for calculating amount of compression and average degree of consolidation. Analytical solutions show that the amount of compression of soft soil under 1m water head difference is equal to that induced by 5kPa uniformly distributed load on the top of the soil layer. Comparing with the Terzaghi one-dimensional consolidation theory, the one-dimensional consolidation of soft soil induced by water head difference in instant decline model uses only 1/4 time of the former to achieve an equivalent average degree of consolidation.