Multiple approaches of determining coefficient of consolidation under radial drainage on δ-log t plot

Abstract

The ever increasing demand for good sites for the engineering constructional activities necessitate many land reclamation projects involving water front areas, marginal lands and the like. These projects aim at consolidating compressible clayey soils through vertical drains. Coefficient of consolidation under radial drainage is an important input parameter in the design of any effective sand drain installation. In the present study, the solution of the governing differential equation for consolidation with radial drainage for equal vertical strain condition is represented on a semi-logarithmic plot and its characteristic features are analyzed. Some of the characteristic features observed on the theoretical curves are simulated on experimental δ-log t curves. The results of such an analysis has paved way for the development of three curve fitting procedures to determine the coefficient of consolidation under radial drainage in the initial, middle and the later stages of consolidation process. The theoretical formulations have been validated through the data from laboratory consolidation tests with radial drainage. A comparative study of the values of coefficient of consolidation under radial drainage obtained from the proposed methods and also from the methods available in the literature has also been made.