Development and verification of a new simplified method for calculating settlement of a thick soil layer with nonlinear compressibility and creep

Abstract

Variable compressibility must be considered in settlement calculation of soft soil stratums, especially for thick soil layers. This study proposes a new simplified method to calculate the settlement of a thick soil layer with creep. It is a new simplified method because tedious numerical methods are avoided to obtain the total settlement including consolidation and creep settlement. The new simplified method is based on a mathematical solution for the consolidation analysis of a soil layer to consider nonlinear compressibility, and it is proposed to take α=Uz as a variable instead of a constant as in previous studies. A series of cases including different thicknesses of soil stratums, different OCR values, different surcharge loadings, and different values of creep parameter are studied to verify the new simplified method by comparing our calculated values with the finite-element (FE) simulated results. Subsequently, a typical and well-known Väsby test fill project with 50-year measured data was selected as a thick soil layer example to illustrate the feasibility of the new simplified method to be used in practice. Both the new simplified method and finite-element modeling were used to obtain ground settlements. It was found from the comparison that the calculated results from the new simplified method and the FE modeling were in good agreement with the measured data.