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SUMMARY By incorporating the nonlinear variation of a soil's compressibility and permeability during the process of consolidation, an analytical solution for the radial consolidation of vertical drains has been developed for a general time-variable loading. The general solution was verified for the cases of instantaneous loading and ramp loading. Detailed solutions were further derived for two special loading schemes: multistage loading and preloading-unloading-reloading. The nonlinear consolidation behavior of a vertical drain subjected to these two types of loading schemes was then investigated by a parametric study. The results show that the loading rate, the ratio of the compressibility index to the permeability index ( Cc/ Ck), and the initial stress state have a significant influence on the consolidation rate. A smaller value of Cc/ Ck, a larger initial stress, or a fast loading rate always leads to a rapid consolidation rate. During the unloading period, a negative excess pore water pressure may occur, and a slower unloading rate may reduce this negative value. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, an attempt has been made to investigate the thermo-hydro-elastodynamic response of a spherical cavity in isotropic saturated poroelastic medium when subjected to a time dependent thermal/mechanical source. The fully coupling thermo-hydro-elastodynamic model is presented on the basis of equations of motion, fluid flow, feat flow and constitutive equation with effective stress and temperature change. Solutions of displacement, temperature and stresses are obtained by using a semi-analytical approach in the domain of Laplace transform. Numerical results are also performed for portraying the nature of variations of the field variables, i.e. the coefficient of thermo-osmosis, the permeability. In addition, comparisons are presented with the corresponding partially thermo-hydro-elastodynamic model and thermo-elastodynamic model to ascertain the validity and the difference between these models. [Copyright &y& Elsevier]

The consolidation behavior of ground with vertical drains is known to be greatly affected by the finite permeability of the sand drains, also called the effect of well resistance. However, up to now, no analytical methods have been reported for evaluating this effect on the nonlinear consolidation behavior of vertical drains. In this paper, by considering the nonlinear compressibility and permeability of soil during consolidation, the effect of well resistance was incorporated into the derivation of the equations that govern the nonlinear consolidation of a vertical drain with coupled radial–vertical flow. In addition, the smear effect was considered by assuming three decay patterns for the radial permeability coefficients of the soil toward the sand drain in the smeared zone. After obtaining the governing equations, a simplified analytical solution is derived for a general time-variable surcharge loading. Based on the general solution obtained, detailed solutions are provided for three special types of loading schemes: constant loading, single-stage loading, and multi-stage loading. The validity of the solution is verified by reducing it to several special cases and comparing these to existing solutions. Finally, the effect of the well resistance, the ratios of the compression index to the radial and vertical permeability indices, various loading schemes, and various variation patterns of the radial permeability coefficient of the soil in the smeared soil zone are investigated using parametric analysis. [ABSTRACT FROM AUTHOR]