One-dimensional consolidation of layered soils under ramp load based on continuous drainage boundary

The traditional drainage boundary regards the drainage boundary as completely permeable or completely impervious. However, the drainage boundary is an impeded drainage boundary between completely permeable and impervious in engineering practice. In view of this, a new drainage boundary, namely the continuous drainage boundary, is introduced in this paper to study the consolidation problem of layered soils. First, the governing equations for the one-dimensional consolidation problem of layered soils subjected to a ramp load are established. Then, the analytical solution of excess pore water pressure and average consolidation degree is derived by means of Laplace transform and matrix transfer method. The present solution is verified by degenerating it and comparing with existing solutions. Based on the present solution, the consolidation behavior of the layered soils is investigated by conducting a detailed parametric study. The results show that, both the interface parameters of boundaries and the stratification of the layered soils can heavily affect the distribution of the excess pore water pressure along the depth, thereby influence the plane of the maximum excess pore water pressure. Therefore, the interface parameters of boundaries and the soil stratification should be comprehensively considered in the optimization for the horizontal drains. © 2020 John Wiley & Sons Ltd.