Consolidation of sensitive clays: a numerical investigation

Consolidation of sensitive clay layers, which have significant compressibility at different stress states, is investigated via a nonlinear one-dimensional consolidation approach with a piecewise linear e ~ log₁₀σ′ model. The behaviour of sensitive clays during consolidation and the limitations of conventional consolidation theory are addressed. It is shown that (1) the sensitive clay layer can be divided by the preconsolidation pressure into two zones, that is, high- and low-compressibility zones. The progressive destruction of particle cementation bonding through the soil layer is shown by the moving front of the interface between these two zones; (2) the excess pore pressure dissipation primarily takes place in the low-compressibility zone, which results in a small settlement during the early stages of consolidation; (3) conventional consolidation theory highly overestimates the settlement and gives a poor prediction of effective stress distribution.