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

Abstract

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.

Time scales in the primary and secondary compression of soils

“…This theory as well as its variations has dominated the literature in the past several decades. In the context of one-dimensional deformation and flow processes, some major improvements on the theory have been made taking into consideration the effect of partial saturation, [1][2][3][4][5][6][7][8][9][10] time-dependent surface loading, [11][12][13][14][15][16][17] layered soil systems, [18][19][20][21][22][23][24] and simple nonlinearity including plasticity [25][26][27][28] and varying compressibility and permeabilitiy, 23,[29][30][31][32][33] among others. Even though the 1D kinematics have imposed limits on the applicability of these theories, they are still valuable contributions to the literature because they can be represented with closed-form analytical solutions.…”

Consolidation calculation of a foundation partially penetrated by concrete‐cored gravel (CCG) columns

“…For example, the permeability coefficients and compression moduli of subsoils and gravel columns are constant during the drainage process in the proposed methods. The proposed analytical solutions will be promoted if the time‐dependent variations of these consolidation‐related parameters are involved 28,29 . In addition, the proposed analytical solutions are expected to spread into more circumstances, such as unsaturated soft soils causing varying negative and positive friction along the pile shaft 30,22 and nonlinear constitutive models of subsoils 31,32 …”

General analytical solutions for one‐dimensional nonlinear consolidation of saturated clay under non‐isothermal distribution condition

“…To explore the consolidation characteristics of clay considering the effects of temperature, many related experimental studies were carried out 19,29–37 . Paaswell carried out the heating test of soils under constant loading and found that the increase in temperature d led to the soil settlement, where the concept of “thermal consolidation” was proposed for the first time 29 .…”

“…To explore the consolidation characteristics of clay considering the effects of temperature, many related experimental studies were carried out. 19,[29][30][31][32][33][34][35][36][37] Paaswell carried out the heating test of soils under constant loading and found that the increase in temperature d led to the soil settlement, where the concept of "thermal consolidation" was proposed for the first time. 29 Some experimental researches showed that the influence of temperature on the compressibility of clay was related to the stress history, 33,34 and the pre-consolidation pressure of soils gradually decreased with increasing the temperature.…”