One-dimensional large-strain thaw consolidation using nonlinear effective stress – void ratio – hydraulic conductivity relationships

Abstract

A one-dimensional model for the consolidation of thawing soils is formulated in terms of large-strain consolidation and heat-transfer equations. The model integrates heat transfer due to conduction, phase change, and advection. The hydromechanical behaviour is modelled by large-strain consolidation theory. The equations are coupled in a moving boundary scheme developed in Lagrangian coordinates. Finite strains are allowed and nonlinear effective stress – void ratio – hydraulic conductivity relationships are proposed to characterize the thawing soil properties. Initial conditions and boundary conditions are presented with special consideration for the moving boundary condition at the thaw front developed in terms of large-strain consolidation. The proposed model is applied and compared with small-strain thaw consolidation theory in a theoretical working example of a thawing fine-grained soil sample. The modelling results are presented in terms of temperature, thaw penetration, settlements, void ratio, and excess pore-water pressures.

Measurement and Investigation on 1-D Consolidation Permeability of Saturated Clay considering Consolidation Stress Ratio and Stress History

“…The final void ratio was reduced by 8.76%, 9.73%, and 11.35% compared with the initial void ratio. (7) and (8), the difference between the consolidation pressure of saturated clay and the self-weight stress of the soil layer can be obtained. Only the calculated values when K c = 1 are listed in Table 9.…”

“…A method for simulating nonlinear characteristics of soil during compression by the hyperbolic curve was developed according to the compression behavior of soil [6]. Dumais and Konrad [7] established a one-dimensional model for the consolidation of thawed soil by using the relationship among effective stress, void ratio, and permeability coefficient. Yin and Feng [8,9] stated that the variable compressibility must be considered in settlement calculation of soft soil stratum and proposed a new simplified method to calculate the settlement of a thick soil layer by considering the nonlinear compressibility.…”

Nonlinear Analysis of the Thaw Settlement in Ice-Rich Embankments

“…e nonlinear relationship between the void ratio and the compression modulus is used to describe the nonlinear stress-strain relationship of postthaw ice-rich frozen soil. However, direct application of equation (12) to the numerical calculations will considerably reduce the calculation efficiency and stability. e compression modulus of soil with high ice content will increase gradually from a very low initial value after thawing.…”

“…e stress-strain relationship of ice-rich frozen soil shows a strong nonlinearity when it is postthaw. Obviously, the linear elastic stress-strain relationship cannot reasonably describe the nonlinear mechanical behavior [11][12][13]. Correspondingly, the calculation accuracy is greatly reduced by using elastic theory.…”

“…Correspondingly, the calculation accuracy is greatly reduced by using elastic theory. Considering this, Dumais and Konrad [12] proposed a nonlinear large strain theory by taking the effective stress-void ratiohydraulic conductivity nonlinear relationship into account.…”