Title

Soil consolidation with varying properties and secondary compression

Date of Completion

January 2001

Keywords

Applied Mechanics|Engineering, Civil|Engineering, Mining

Degree

Ph.D.

Abstract

Terzaghi's solution to the one dimensional consolidation theory (1925) represents an engineering approximation to a complex problem. Terzaghi assumed that the changes occurring in the soil are such that the physical properties are constant and the strains are small. ^ To achieve a more accurate representation of the actual conditions in the consolidating soil, several modifications were proposed during subsequent years. Among the additional consideration are: (1) Variable properties. (Poskitt 1969). (2) Constant properties and secondary compression. (Barden 1968). (3) Variable properties with Large Strain, (VPLS). (Pane ET AL 1983). ^ In this study consolidation behavior combines secondary compression with variable properties, for small strain cases, is modeled considering fundamental properties of the soil such as permeability, compressibility and secondary compression parameters. An approximate solution to consolidation with Variable properties (without secondary compression) is, also presented in the form of a quadratic regression. This consolidation solution can be used to model those cases where the secondary compression effects are not present or when they are not included in the analysis. ^ A series of VPLS tests were also performed to explore the effect of the velocity of the solids and permeability measurements performed in VPLS samples. Laboratory results were modeled without considering Secondary Compression or the velocity of the solids (Vs). Good agreement was obtained between theoretical and experimental data. ^ The results of this work are intended to increase our understanding of time dependent settlement. The techniques presented here can be implemented in those projects where the prediction of time vs settlement relationship is critical, and the required effort to develop such relationship can be justified. ^